Smart nebulizer

ABSTRACT

A nebulizer system capable of identifying when activation has occurred and aerosol is being produced. The nebulizer system monitors the inhalation and exhalation flow generated by the patient and communicates proper breathing technique for optimal drug delivery. The nebulizer system may monitor air supply to the nebulizer to ensure it is within the working range and is producing, or is capable of producing, acceptable particle size and drug output rate. When a patient, caregiver or other user deposits or inserts medication into the nebulizer, the nebulizer system is able to identify the medication and determine the appropriate delivery methods required to properly administer the medication as well as output this information into a treatment log to ensure the patient is taking the proper medications. The system is able to measure the concentration of the medication and volume of the medication placed within the medication receptacle, e.g., bowl.

This application claims the benefit of U.S. Provisional Application No.62/432,304, filed Dec. 9, 2016, the entire disclosure of which is herebyincorporated herein by reference.

TECHNICAL FIELD

The embodiments disclosed herein relate generally to a smart nebulizer,and to methods for the use and assembly thereof.

BACKGROUND

Current nebulizers provide little or no feedback about variousmedication compliance aspects, including without limitation treatmentadherence, drug delivery, dose assurance and proper breathingtechniques. Medication compliance, while often difficult to monitor, canprovide important information to the user, care providers and insuranceproviders.

SUMMARY

Whether in breath actuated or continuous mode, a smart nebulizer systemidentifies when activation has occurred and aerosol is being produced.The smart nebulizer system may provide real time feedback regarding apatient's treatment progression, the identity and amount of drugdelivered, and an indication of when treatment is complete. As thepatient undergoes treatment, the smart nebulizer system monitors theinhalation and exhalation flow generated by the patient and communicatesproper breathing technique for optimal drug delivery. The smartnebulizer system may monitor air supply to the nebulizer to ensure it iswithin the working range and is producing, or is capable of producing,acceptable particle size and drug output rate.

When a patient, caregiver or other user deposits or inserts medicationinto the nebulizer, the smart nebulizer system is able to identify themedication and determine the appropriate delivery methods required toproperly administer the medication as well as output this informationinto a treatment log to ensure the patient is taking the propermedications. The system is able to measure the concentration of themedication and volume of the medication placed within the medicationreceptacle, e.g., bowl.

In addition to analyzing when the device has activated and the flowgenerated by the patient, the system may also analyze the particle sizesof the aerosol and determine the respirable fraction. The device iscapable of determining when end of treatment has been reached andthereafter communicating this information to the patient, or other usersuch as a caregiver. Upon completion of the treatment, the nebulizersystem recognizes the residual volume and outputs/stores thisinformation in a treatment log.

Using these methods, or any subset of these methods, allows thenebulizer system to determine the identity and amount of medicamentdelivered to patient and to provide dose assurance to the patient,healthcare provider and insurer. This information can then be stored inthe nebulizer system and viewed by the appropriate parties.

The nebulizer system may also provide coaching about proper breathingtechniques and posture to optimize drug delivery to the lower airways.For the health care provider, the nebulizer system can provide atreatment history record to ensure the patient is complying with theproper treatment regimen, and aid in the continued development of such atreatment regimen. This treatment log may be automated, and therebyavoid patient input and reduce the treatment burden when compared withsimilar logging methods, e.g., daily diaries. A treatment historyrecord, coupled with regular check-ups helps a healthcare providerdevelop a proper treatment regimen, as it removes uncertainty as towhether any disease progression is due to inadequate medication orsub-optimal adherence by the patient. To provide such information, thenebulizer system is able to detect activation and deactivation, monitorthe breathing pattern of the patient, measure the performance of the airsupply to the nebulizer, identify the medication types andconcentrations as well as the particle size the nebulizer is producing.The nebulizer system may also identify end of treatment and the residualvolume of medication left in the nebulizer.

In one embodiment, the electronic portion of the smart nebulizer systemis detachable from the mechanical portion, which allows for therelatively more expensive, intelligent component to be used withmultiple nebulizers when such nebulizers have exceeded their useful lifeand/or are no longer performing optimally. The smart nebulizer systemmay also act as a treatment reminder for the patient to track treatment,and also prompt adherence. The detachable portion, which his portable,may be carried by the patient/user, for example by way of a clip,tether/lanyard, carrying case, wristband, etc. The portable portion mayfurther provide a reminder about upcoming treatment requirements by wayof visual, audible, tactile (e.g., vibratory) and/or haptic feedback.

The smart nebulizer system may have a user interface that cancommunicate information to the patient/user, including withoutlimitation treatment progression, inhalation flow rate and breathingrate, preferably with low latency. The interface may be incorporatedinto the nebulizer, such as the housing, or information from thenebulizer may be communicated to a standalone device, such as aperipheral device, including for example a smartphone or tablet, forviewing. Communication of the information is not limited to visualinformation, such as graphics or text, but may also include audible andhaptic information, communication methodologies and components.

It should be understood that the various embodiments, features andprocesses discussed herein are applicable to both breath actuated andcontinuous nebulizers.

The foregoing paragraphs have been provided by way of generalintroduction, and are not intended to limit the scope of the followingclaims. The present embodiments, together with further objects andadvantages, will be best understood by reference to the followingdetailed description taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The Figures show different embodiments of a medication delivery ornebulizer system, block/flow diagrams and methods for the use andassembly thereof.

FIG. 1 is a perspective view of one embodiment of a nebulizer having adiaphragm.

FIG. 2 is an exploded view of the nebulizer shown in FIG. 1.

FIGS. 3A and B are cross-sectional side views of the nebulizer duringinhalation and exhalation respectively.

FIG. 4 is a flow chart illustrating the use and feedback loops for asmart nebulizer device.

FIG. 5 is a schematic illustrating a computer structure.

FIG. 6 is a schematic illustration of a communication system.

FIG. 7 is a top or bottom view of a diaphragm.

FIG. 8 is a side view of one embodiment of an actuator, diaphragm andnozzle cover.

FIG. 9 is a side view of another embodiment of an actuator anddiaphragm.

FIG. 10 shows one pressure and flow profile of one embodiment of anebulizer.

FIG. 11 is a side view of another embodiment of a nebulizer.

FIG. 12 is a perspective view of a mouthpiece for a nebulizer.

FIGS. 13A-E are flow paths through a nebulizer at various stages of abreathing cycle.

FIG. 14 is a cross-sectional view of one embodiment of a nebulizer.

FIG. 15 is a cross-sectional view of a nozzle and cover.

FIG. 16 is a graph showing sound level v. time during a breathing cycle.

FIG. 17 is a cross-sectional view of one embodiment of a nebulizer.

FIG. 18 is a schematic representation of an actuator.

FIG. 19 is a cross-sectional view of one embodiment of a mouthpiece.

FIG. 20 is a graph of relative humidity v. time during a breathingcycle.

FIG. 21 is a cross-sectional view of one embodiment of a mouthpiece.

FIG. 22A is a side view of an actuator and diaphragm.

FIG. 22B is a cross-sectional view of a dial.

FIGS. 23A and B are perspective view of a top of a nebulizer, showing adome in different positions.

FIG. 24 is a cross-sectional view of one embodiment of an actuator,retainer and diaphragm.

FIG. 25 is a cross-sectional view of an alternative embodiment of anactuator and diaphragm.

FIG. 26 is a cross-sectional view of an alternative embodiment of anactuator.

FIGS. 27A and B are cross-sectional views of an alternative embodimentof a flow path.

FIGS. 28A and B are cross-sectional views of one embodiment of a flowpath.

FIG. 29 is a cross-sectional view of one embodiment of a nebulizer.

FIG. 30 is a flow chart showing the calculation of flow rate using amicrophone.

FIG. 31 is a partial cross-sectional view of an inhalation window.

FIG. 32 is a cross-sectional view of one embodiment of a flow path.

FIG. 33 is a cross-sectional view of one embodiment of a mouthpiece.

FIG. 34 is a cross-sectional view of one embodiment of a nebulizer.

FIG. 35 is a cross-sectional view of one embodiment of a flow path.

FIG. 36 is a cross-sectional view of one embodiment of a flow path.

FIG. 37 is a cross-sectional view, with enlargement, of one embodimentof a nebulizer.

FIG. 38 is a cross-sectional view of one embodiment of a flow path.

FIG. 39 is a cross-sectional view of one embodiment ora flow path.

FIG. 40 is a side view showing a patient with one embodiment of anebulizer.

FIG. 41 is a cross-sectional view of one embodiment of a flow path.

FIG. 42 is a cross-sectional view of one embodiment of a flow path.

FIG. 43 is a view of a flow path through one embodiment of a valve.

FIG. 44 is a view of a flow path through one embodiment of a valve.

FIGS. 45A and B are views of a flow path with a valve in closed and openpositions respectively.

FIG. 46 is a cross-sectional view of one embodiment of a nebulizer.

FIGS. 47A-C are schematic representations of various flow paths.

FIG. 48 is a cross-sectional view of one embodiment of a flow path.

FIGS. 49A and B are cross-sectional and perspective views of oneembodiment of a nebulizer respectively.

FIG. 50 is a cross-sectional view of one embodiment of a flow path.

FIGS. 51A and B are perspective views showing a diaphragm duringnon-inhalation and inhalation respectively.

FIG. 52 is a side view of a vibratory sensing element.

FIG. 53 is a view of a sensing circuit.

FIG. 54 is a cross-sectional view of one embodiment of a flow path.

FIG. 55 is a cross-sectional view of one embodiment of a flow path.

FIG. 56 is a cross-sectional view of one embodiment of a flow path.

FIG. 57 is a cross-sectional view of one embodiment of a flow path.

FIG. 58 is a cross-sectional view of one embodiment of a flow path.

FIG. 59 is a cross-sectional view of one embodiment of a flow path.

FIG. 60 is a cross-sectional view of one embodiment of a flow path.

FIG. 61 shows an exemplary schematic of various flow paths in anebulizer.

FIG. 62 is a cross-sectional view of one embodiment of a nebulizer.

FIG. 63 is a perspective view of the nebulizer shown in FIG. 62.

FIG. 64 is a partial cross-sectional view of a nozzle and baffle.

FIG. 65 is a partial cross-sectional view of a nozzle and baffle.

FIG. 66 is a perspective view of a compressor coupled to a nebulizer.

FIG. 67 is a cross-sectional view of one embodiment of a flow path.

FIG. 68 is view of a portion of a supply tubing.

FIG. 69 is a cross-sectional view of one embodiment of a flow path.

FIG. 70 is a cross-sectional view of one embodiment of a flow path.

FIGS. 71A-C are a cross-sectional view of one embodiment of a nebulizerand an enlarged portion thereof, with attendant particle separation.

FIG. 72 is a schematic showing light based analysis of particle size.

FIG. 73 is a flow chart showing use cycle with end of treatmentnotification.

FIG. 74 is a partial cross-sectional view of a nozzle and baffle.

FIGS. 75A and B show switch signatures for “sputter.”

FIG. 76 shows one embodiment of a packaging or nebulizer with bar code.

FIG. 77 shows one embodiment of a nebulizer with an RAID tag and reader.

FIG. 78 is a schematic of a communication protocol.

FIG. 79 is a graph of for spectroscopic drug identification.

FIGS. 80A and B show embodiments of different flow paths.

FIG. 81 shows a cross-sectional view of one embodiment of a reservoir.

FIG. 82 shows a cross-sectional view of one embodiment of a reservoir.

FIG. 83 is a cross-sectional view of one embodiment of a nozzle andbaffle.

FIG. 84 is a force/pressure graph during a breathing cycle.

FIG. 85 is a cross-sectional view of one embodiment of a reservoir.

FIG. 86 is a cross-sectional view of one embodiment of a reservoir.

FIGS. 87A-C are cross-sectional views of various reservoir embodiments.

FIG. 88 is a cross-sectional view of one embodiment of a reservoir.

FIG. 89 is a cross-sectional view of one embodiment of a reservoir.

FIG. 90 is a cross-sectional view of one embodiment of a reservoir withconductive strips.

FIG. 91 is a cross-sectional view of one embodiment of a nebulizer.

FIG. 92 is a cross-sectional view of one embodiment of a reservoir.

FIG. 93 is a schematic view of one embodiment of a fluid level in areservoir.

FIG. 94 is a cross-sectional view of one embodiment of a reservoir.

FIG. 95 is a view of a nebulizer and scale.

FIG. 96 are side and bottom views of one embodiment of a nebulizer.

FIG. 97 is a cross-sectional view of one embodiment of a reservoir andnozzle.

FIG. 98 is a cross-sectional view of one embodiment of a reservoir.

FIG. 99 is a cross-sectional view of one embodiment of a reservoir andabsorbance wave lengths.

FIG. 100 is a view of a conductivity arrangement for concentrationdetermination.

FIGS. 101A and B are cross-sectional views of an actuator and diaphragmin on and off configurations.

FIGS. 102A and B is a cross-sectional view of an actuator and diaphragm,and a voltage graph.

FIGS. 103A and B are cross-sectional views of an actuator with a contactswitch.

FIGS. 104A and B are cross-sectional views of an actuator and diaphragmwith a contact switch.

FIG. 105 is a schematic showing a smart nebulizer system.

FIG. 106 is a flow chart showing a smart nebulizer treatment cycle.

FIG. 107 is a view of a user interface with one embodiment of an outputgame.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

It should be understood that the term “plurality,” as used herein, meanstwo or more. The term “coupled” means connected to or engaged with,whether directly or indirectly, for example with an intervening member,and does not require the engagement to be fixed or permanent, althoughit may be fixed or permanent, and further may be mechanical orelectrical, including for example a wireless communication. The phrase“fluid communication,” and variants thereof, refers to fluid being ableto pass between the components, whether directly or indirectly, forexample through one or more additional conduits or components. It shouldbe understood that the use of numerical terms “first,” “second,”“third,” etc., as used herein docs not refer to any particular sequenceor order of components. It should be understood that the term “user” and“patient” as used herein refers to any user, including pediatric,adolescent or adult humans, and/or animals.

The term “smart” refers to features that follow the general format ofhaving an input, where information is entered into the system, analysis,where the system acts on or modifies the information, and an output,wherein new information leaves the system. The phrase “performancecharacteristics” refers to measurements, such as frequency or amplitude,which quantify how well a device is functioning.

Referring now to FIGS. 1-2, one implementation of a nebulizer 10 isshown. The nebulizer may include six discrete components (FIG. 2), fiveof which are capable of being assembled in a top-down method with eachcomponent (other than the mouthpiece 12) sharing a common central axis.This arrangement may assist with reducing complexity when implementingautomated assembly. As can be seen, the components are also capable ofbeing assembled manually and incorporate features to reduce aprobability of human error in the assembly process.

The components of the nebulizer 10 include a bottom housing 14 having acylindrical body. The nebulizer 10 also contains a top portion, referredto as the retainer 16, and an internal assembly, referred to as theinner housing 18. A flexible component is also included in the nebulizer10, and is referred to as the diaphragm 20. A long, shaft-likecomponent, referred to as the actuator 22, is also contained within thenebulizer 10. The final component is the tubular mouthpiece 12. Thecomponents of the nebulizer 10, other than the diaphragm 20, may beformed with a single piece of material by an injection molding processand assembled without the use of welding or adhesives and joinedtogether using interference fits.

The retainer 16, actuator 22, inner housing 18, bottom hosing 14 andmouthpiece 12 may all be constructed from a plastic material such as,but not limited to, polypropylene. Any of a number of types of plasticmay be used to construct these parts of the nebulizer 10. The diaphragm20 may be constructed from, but not limited to, a flexible material suchas silicone.

Referring to FIG. 3A, a pressurized gas inlet 24 of the bottom housing14 extends into the chamber 26 of the bottom housing 14. The externalopening 28 of the pressured gas inlet 24 is designed to press-fit with apressured gas hose fitting (not shown). Inside the bottom housing 14,the pressurized gas inlet 24 tapers down into a nozzle with apressurized gas orifice 30 having a predetermined diameter. Preferablythe gas inlet 24 is coaxial with the cylindrical body of the bottomhousing 14 and extends through the bottom wall 32 of the chamber 26. Theinner housing 18 incorporates a nozzle cover 34 that slides over thepressurized gas inlet 24 on the bottom housing assembly 14.

The nozzle cover 34 is a tapered tubular member with openings at eitherend. When positioned over the pressurized gas inlet 24, the spacebetween the nozzle cover 34 and the pressurized gas inlet 24 creates atleast one passageway 36 between the radial opening created by the gapbetween the nozzle cover 34 and the bottom wall 32 of the bottom housing14 and the annular opening 38 defined by the outer diameter of thenozzle end of the pressurized gas inlet 24 and the inner diameter of thenozzle cover 34. To maintain the proper size of the annular opening 38and position of the nozzle cover 34 over the pressurized gas inlet 24,triangular ribs 40 may be included on the inside surface of the nozzlecover 34 and are designed to cooperate with a ledge 42 of thepressurized gas inlet 24, formed near the tip to locate the nozzle cover34 concentrically and maintain the passageway opening 44 between thelower edge of the nozzle cover 34 and the bottom wall 32 of the bottomhousing 14.

The lower chamber of the bottom housing 14 is preferably used as areservoir 46 and holds a fluid for nebulizing, such as a solutioncontaining medication. In one embodiment, the lower wall of the bottomhousing 14 slopes down to the base of the pressurized gas nozzle so thatgravity urges the fluid into the reservoir 46, towards of the opening 44of the passageway 36. As shown in FIG. 3A, the wall of the reservoir maybe set at an approximate angle of 45 degrees from the central axis ofthe nebulizer, although other wall angles can be used to reduce theresidual volume of medication at the end of a treatment. The bottomhousing 14 may be constructed from transparent plastic material to allowfor the patient and medical personnel to monitor medication levels inthe nebulizer 10.

Referring to FIGS. 3A and B, the passageway 36 formed between thepressurized gas inlet 24 and nozzle cover 34 guides fluid from thereservoir 46 through the opening 44 to the passageway 36 and to theannular orifice 38. In this configuration, the flow of a fluid throughthe passageway 36 and the flow of a pressured gas through thepressurized gas inlet 24 are roughly parallel. The initial portion ofthe passageway 36 through which fluid (for example a liquid) travels isan annular or cylindrical pathway that may be undivided vertically. Theribs on the nozzle cover 34 of the internal housing 18 that maintain theconcentricity and height of the nozzle cover 34 with respect to thepressurized gas inlet 24 may divide the passageway 36 into three (3)separate passages near the tip of the nozzle cover 34, however theseparate passages merge and become undivided past the ribs, prior to thepressurized gas orifice 30, The characteristics of the aerosol generatedin the nebulizer 10, in addition to the mass output of the nebulizer,may be varied by varying the size of and number of these passages nearthe end of the passageway 36, as well as by extending the passages tothe surface of the pressurized gas orifice 30. Other passagewaydimensions and arrangements may be implemented to achieve the desiredaerosol size and density during nebulization. The pressured gas orifice30 is preferably circular in shape and concentrically aligned inside theannular orifice 38 in communication with the passageway 36.

The tip of the nozzle cover 34 and tip of the pressurized gas inlet 24may be flat surfaces. In one implementation, the pressurized gas orifice30 is positioned in the plane of the annular orifice 38. Alternatively,the plane of the gas orifice 30 may be parallel to, and offset from, theplane of the tip of the nozzle cover. The relative heights (offsets) ofthe tips of the pressurized gas inlet 24 and the nozzle cover 34 may bevaried to achieve the desired nebulization characteristics.

On the opposite end of the bottom housing 14 from the pressurized gasinlet 24, the inner housing 18 is removably attached to the cylindricalwall of the bottom housing 14 through the use of three (3) equidistantlyseparated ledges on both the bottom housing 14 and inner housing 18 towhich the inner housing 18 may be loosely rotated under for a frictionalfit to the bottom housing 14. Rotational orientation of the innerhousing 18 relative to the bottom housing 14 may be controlled by a tabincorporated into the inner housing 18 and a corresponding flat surfaceon the bottom housing 14 which arrests the rotational motion of theinner housing 18 when positioned correctly. A ramp profile in the bottomhousing 14 ensures the ledges on the inner housing 18 move under theledges on the bottom housing 14 as the tab follows the ramp profile.Though this example utilizes three (3) equidistantly spaced ledgesaround the outer surface of the bottom housing 14 and inner housing 18,any number of these threaded features may be used to the same effect inother implementations. When assembled, the outer surface of the innerhousing 18 forms an interference fit with the inner surface of thebottom housing 14 to ensure that air and aerosol is unable to leakbetween the two components and into the ambient environment.

The outer flange of the retainer 16 contains four (4) cut-outs 50 whichsnap fit with corresponding male extrusions 52 on the outer surface ofthe inner housing 18 to assemble the retainer 16 to the inner housing18. Two (2) textured flats 54 are included on the outer surface of theretainer 16 that break the circular profile of the outer flange, whichaid in the assembly of the inner housing 18 to the bottom housing 14 asthey mate with corresponding flats 56 on the outer surface of the innerhousing 18. This aids in the implementation of automated assembly as theflats 54, 56 provide features for robotic assembly systems to grasp aswell as for determining orientation with vision systems and reduce theprobability of human error on assembly. The flats 54, 56 on the innerhousing 18 and retainer 16 also allow the parts to be bowl fed to anautomated assembly. The retainer 16 is designed such that the retainer16 may be assembled to the inner housing 18 in either of theconfigurations possible that allow the flats on the inner housing 18 andbottom housing 14 to be parallel to each other on assembly as thefeatures of the retainer 16 are symmetrical. The flats 54, 56 also helpto hold the rotational orientation of the retainer 16 relative to theinner housing 18 after assembly.

Referring to FIGS. 2, 3A and B, the diaphragm 20 and retainer 16 areassembled coaxially and are mounted to each other through aninterference fit between the actuator 22 latch feature of the diaphragm20 and the receiving geometry of the actuator 22. In this configuration,the actuator 22 may be assembled with the diaphragm 20 by inserting theactuator through the inner, circular opening of the diaphragm 20 for agrommet style connection. A triangular-shaped ridge 58 around thesurface of the inner opening 60 of the diaphragm 20 mates withcomplementary receiving triangular grooves 62 on the latching surface ofthe diaphragm 20. The actuator 22 incorporates two (2) curved surfacesof approximately equal diameter on the inner surface of the diaphragm 20in this version of the latch feature.

When pushed through, the ridges slide into the receiving grooves on theactuator 22 and weakly hold the diaphragm 20 in place, relative to theactuator 22. The amount of interference between the actuator 22 anddiaphragm 20 is an important element of the design as excessive forcecan cause deformation of the diaphragm 20, affecting the flowcharacteristics of the valves. No rotational orientation is required forthe assembly of the diaphragm 20 and the actuator 22. There exists onlya top-down orientation when assembling the diaphragm 20 to the actuator22. Though only two (2) surfaces of contact 66 positioned at the end ofsupport arms 64 extending from the central axis of the actuator 22,separated by 180 degrees around the common axis of the diaphragm 20 andthe actuator 22, are used to stabilize the diaphragm 20, any number ofsuch features could be used of various mating geometries though they arepreferably equidistantly positioned around the actuator 22 to ensure thediaphragm 20 does not deform.

The diaphragm 20 and actuator 22 assembly is coaxially and slideablypositioned within the nebulizer, inside the cavity created by the innerhousing 18, with the coaxial body of the actuator 22 piston extendinginto the inner housing 18 along the longitudinal axis of the nebulizeras well as through a coaxial opening in the retainer 16 body. Theclosed, lower feature of the actuator 22 that extends into the cavity ofthe inner housing 18 defines a diverter 68 for diverting the flow ofpressured gas emerging from the pressurized gas orifice 30. In oneimplementation, the diverter 68 has a flat, circular surface having apredetermined area. The surface is also preferably aligned parallel tothe tip of the pressurized gas inlet 24 and perpendicular to thedirection of flow of the pressurized gas through the pressurized gasorifice 30. Concentric alignment of the diverter 68 in relation to thepressurized gas orifice 30 is aided by a downward sloping flange 70connected to the main actuator body with two arm protrusions 72. Thedownward sloping flange 70 acts as a guide and slides along the outersurface of the tapered end of the nozzle cover 34. The downward slopingflange 70 may be a short, tapered tubular feature with an opening ateither end to allow pressured gas to travel unimpeded through itscenter, in addition to the tapered end of the nozzle cover 34. Theflange 70 also helps to set a predetermined distance ‘h’ between thediverter surface and the surface of the pressurized gas orifice as thebottom of the flange 70 will contact a corresponding shoulder on thenozzle cover 34. The mouthpiece 12 is a tubular part with an ovularopening on one end for the patient to breathe through, and a cylindricalopening on the other end, that may be a 22 [mm] ISO standard fittingthat is press-fit into the corresponding cylindrical tube extending fromthe bottom housing 14, perpendicular to the axis of assembly for allother components.

Referring to the embodiment of FIGS. 1-3B, the operation of thenebulizer will now be explained. During operation, pressured gasprovided from a gas source to the pressurized gas inlet 24 iscontinually entering the nebulizer 10 through the pressurized gasorifice 10. There are two main positions that the actuator 22 can be inthat cover the two states of the nebulizer during operation. In thefirst position, the diverter 68 is spaced a great enough distance awayfrom the top of the pressurized gas orifice 30 so that nebulization isnot initiated. The second position occurs during inhalation (and in acontinuous nebulization mode when that mode is manually set) and isachieved when the actuator 22 moves downward in relation to the rest ofthe nebulizer so that the diverter 68 moves to a predetermined distance‘h’ from the orifice of the nozzle appropriate for nebulization of thefluid within the reservoir 46 to occur. The pressurized gas, which maybe oxygen or any other breathable gas, continually flowing from the gasorifice 30 is now deflected radially outward from the gas orifice in a360 degree pattern by the diverter 68. The gas fans out over the annularorifice 38 at a high velocity creating a low pressure zone over theannular orifice. The low pressure zone, along with the capillary effect,draws the liquid from the reservoir 46 though the passageway 36 and intothe stream of the pressurized gas. The liquid is aerosolized and drawnout of the air outlet 84 in the bottom housing 14 through the mouthpiece12.

To improve the performance of the nebulizer 10 in eliminatingnon-optimally size particles, the outer surface of the inner housing 18may include an extension 86 that extends to the inner surface of thebottom housing 14 and at least part way around the outer circumferenceof the inner housing. The extension 86 acts to intercept oversizedparticles entrained in the gas flow and condense on the lower surface ofthe extension 86 and fall back into the reservoir 46. This also helps todecrease the number of oversized particles being inhaled through themouthpiece. The extension also ensures ambient air that is drawn intothe nebulizer takes a more circuitous route through the aerosol beforeit leaves the nebulizer. This may assist to limit the particle densityand reduce the chance of particle growth through accidental particlecollisions. As stated above, the actuator is required to move from theUP/OFF (non-nebulizing) position and the DOWN/ON (nebulizing) positionfor nebulization to occur. Inhalation of ambient air into the nebulizervia the mouthpiece 12 and the exhalation of expired air through thenebulizer and out to the ambient atmosphere and the resistance to thisairflow are important factors which must be controlled to minimize thework required to be done by the patient during a treatment.

The biasing element 78 integrated into the diaphragm 20 assists in themovement of the actuator 22 and is configured to ensure nebulizationoccurs on inhalation when in breath actuated mode yet remains off wheninhalation is not occurring to reduce risk of medication released to theambient environment. Minimizing the inhalation flow required to move theactuator 22 is desirable because lowering the flow required to actuatemeans that nebulization of the medication may start earlier duringinhalation and stop closer to the end of exhalation, thus generatingmore aerosol in each breath and maximizing drug output. In the diaphragm20 of FIGS. 1-3B, the exhalation valve 82 is incorporated into theupwards sloping, circumferential valve of the diaphragm and acts as aone-way pressure relief valve.

Inhalation airflow passes through the center-opening inhalation valve80. In this configuration the inhalation valve 80 uses a donut valvedesign. As stated previously, the use of an inhalation valve 80 thatseals onto the actuator 22 results in assembly that requires norotational orientation between the actuator 22 and diaphragm 20 withonly a vertical orientation needing to be considered. The diaphragm 20is pinned in place between a ring-shaped extrusion 88 (also referred toherein as an exhalation skirt) located on the retainer 16 and a sealingsurface 90 on the inner housing 18. This diaphragm retention techniquehelps to maintain a constant resting position for the diaphragm 20,locates the diaphragm 20 concentrically within the nebulizer 10,separates the movement of the biasing element 78 from thecircumferential exhalation valve 82 and isolates the exhalation flowpathway and the inhalation flow pathway. On inhalation, the exhalationflange contacts a sealing surface incorporated into the inner housing 18and the pathway is blocked. When sufficient negative pressure has beenreached, the donut-shaped inhalation valve 80 is pulled away from thesealing surface 98 of the actuator 22 and air can flow around thesealing surface 98, through the pathway created by the donut-shapedinhalation valve 80, and into the main cavity of the nebulizer 10.Openings 94 located in the retainer 16 and openings 96 in the innerhousing 18 allow air to move from the nebulizer's main chamber and intoand out of the nebulizer 10.

Referring to FIGS. 3A and B inhalation and exhalation flow paths withinthe nebulizer 10 will now be described. Prior to inhalation by thepatient, there exists an upwards force acting on the actuator 22, causedby the pressured gas entering the main chamber through the pressurizedgas orifice 30 and striking the diverter 68. This upwards force raisesthe actuator 22 to its uppermost position, maintaining the diverter's 68position away from the pressurized gas orifice 30, and thus in anon-nebulizing position. Maintenance of the uppermost position of theactuator is also helped by the spring characteristics of the biasingelement 78 on the diaphragm 20 which biases the actuator 22 up and awayfrom the pressured gas orifice 30. The pressured gas entering thenebulizer also creates a positive pressure within the nebulizer 10,pressing the inhalation valves against the sealing surface of theactuator.

On inhalation, the biasing element 78 of the diaphragm 20 rolls inwardin response to negative pressure from within the nebulizer 10, acting onthe lower surface of the diaphragm. This lowers the position of theactuator 22, bringing the diverter 68 closer to the pressured gasorifice 30 until the actuator 22 reaches the nebulizing position so thatthe diverter 68 it diverts the flow of the pressured gas. The negativepressure inside the nebulizer also opens the inhalation valve on thediaphragm, allowing atmospheric air to be drawn into the device toimprove the delivery of fine particle mass and to maintain a lowinhalation resistance to minimize the work needed to be done by thepatient during inhalation. Atmospheric air is drawn into the nebulizerthrough openings 94 integrated into the retainer.

FIG. 3A illustrates the airflow pathways of the entrained air, suppliedair and aerosol on inhalation. The negative pressure generated insidethe device during inhalation also ensures that the outer circumferentialexhalation valve 82 on the diaphragm 20 is sealed against the innersurface of the inner housing 18, blocking the exhalation pathway frominhalation airflow. FIG. 3B illustrates the airflow pathways of theexpired air and supplied air on exhalation.

On exhalation, expired air moves through the nebulizer 10 and exitsthrough the rear of the nebulizer, away from the patient, to ensure nomedication is deposited on the patient's face or eyes. In oneembodiment, two (2) rectangular windows on the back and top of the innerhousing 18 are used to allow the expired air to exit the nebulizer 10,however other variations in vent shape and sizing are contemplated. Thevents in the inner housing 18 allow both the supplied air and expiredair to exit the main chamber 26 of the nebulizer 10 and move under thecircumferential exhalation valve 82. Expired air is blocked from exitingthe top windows 94 of the retainer 16 due to the exhalation skirt 88pinning the diaphragm 20 to the inner housing 18, isolating theexhalation 82 and inhalation 80 valves. Airflow is channeled around theretainer 16 between the exhalation skirt 88 and inner housing 18 andvented out of the back of the nebulizer 10 through vents 96 incorporatedinto the inner housing 18. The positive pressure generated within thenebulizer seals the inhalation valve 80 against the sealing surface 98of the actuator 22 and prevents air from flowing out of the top windows94 of the retainer 18.

Although preferably operated by breath actuation, the nebulizer 10 mayalso be manually actuated. The nebulizer 10 may include a manualactuating member connected with, integral to, or capable of contact withthe actuator piston and extending out of the upper portion of thehousing through an air inlet or other opening. The manual actuatingmember may be integrally formed with the actuator piston. The actuatingmember permits a caregiver or patient to move the actuator piston byhand, and thus move the nozzle cover, so that the nebulizer initiatesnebulization. Although the manually actuable nebulizer may include adiverter that is integrally formed with the lid, any of the otherdiverter or nozzle configurations disclosed herein, or theirequivalents, may be used.

Referring to FIGS. 4-6, block diagrams and a schematic illustrate theoperation of the device. One exemplary breath actuated nebulizer (BAN)device is the AEROECLIPSE BAN device available from Trudell MedicalInternational, London. Various features of a BAN are disclosed in U.S.patent application Ser. No. 15/644,427, filed Jul. 7, 2017, U.S. Pat.No. 9,364,618, issued Jun. 14, 2016, and U.S. Publication No.2013/0247903, all entitled Nebulizer Apparatus and Method and assignedto Trudell Medical International the Assignee of the presentapplication, and the entire disclosures of which are hereby incorporatedherein by reference. The various portions of the device, including themechanical portions, may be made of a plastic material, includingwithout limitation polypropylene. A biasing element may be made, forexample and without limitation, of a flexible material, such assilicone.

The term “input” refers to any information that enters the smartnebulizer system, and may take the form of raw data from a sensor, acommand to start a process or personal data entered by the user. Forexample, the input may be a signal from one or more sensors. Forexample, a pressure sensor generates an electrical signal as a functionof the pressure in the system. The pressure sensor may be used tocalculate any of the performance characteristics referred to above, aswell as to evaluate the user's technique. A sensor assembly may includea pressure sensor placed on a printed circuit board (PCB), along with ablue tooth low energy (BTLE) module, a microprocessor, and a battery,and may communicate with a user's (patient, caregiver and/or otherauthorized user) computing device, such as a mobile device, including asmart phone or tablet computer, for example via bluetooth. A singlepressure sensor may provide all of the measurement requirements. Thepressure sensor may be a differential, absolute or gauge type of sensor.The sensor assembly may be coupled to the nebulizer device, for examplewith a cover disposed over the assembly.

The patient/user, care providers, physicians, insurers benefit fromvarious features of a smart nebulizer, whether a BAN or a continuousdevice. For example and without limitation, the nebulizer may be linkedvia blue tooth to a mobile device, such as a personal digital assistant,tablet or smartphone, for example via an application. Variousinformation that may be stored and/or communicated includes measuringflow and breathing patters, e.g., counting breaths, timing ofinhalation, signal for end of treatment, recording of when (time andday) device was used, signal of correct inhalation flow, activationdetection, identification of medication, concentration of medication,particle size measurement, air supply pressure, nozzle flow, and filland residual volume determination.

In order to provide faster and more accurate processing of the sensordata generated within the smart nebulizer, data may be wirelesslycommunicated to a smart phone, local computing device and/or remotecomputing device to interpret and act on the raw sensor data. The smartphone may display graphics or instructions to the user and implementprocessing software to interpret and act on the raw data. The smartphone may include software that filters and processes the raw sensordata and outputs the relevant status information contained in the rawsensor data to a display on the smart phone. The smart phone or otherlocal computing device may alternatively use its local resources tocontact a remote database or server to retrieve processing instructionsor to forward the raw sensor data for remote processing andinterpretation, and to receive the processed and interpreted sensor databack from the remote server for display to the user or a caregiver thatis with the user of the smart nebulizer.

In addition to simply presenting data, statistics or instructions on adisplay of the smart phone or other local computer in proximity of thesmart nebulizer, proactive operations relating to the smart nebulizermay be actively managed and controlled. For example, if the smart phoneor other local computer in proximity to the smart nebulizer determinesthat the sensor data indicates the end of treatment has been reached,the smart phone or other local computing device may communicate directlywith a pressurized gas line relay associated with the gas supply to thesmart nebulizer to shut down the supply of gas. Other variations arealso contemplated, for example where a remote server in communicationwith the smart phone, or in direct communication with the smartnebulizer via a communication network, can make the decision to shutdown the pressurized gas supply to the smart nebulizer when an end oftreatment status is determined.

In yet other implementations, real-time data gathered in the smartnebulizer and relayed via to the smart phone to the remote server maytrigger the remote server to track down and notify a physician orsupervising caregiver regarding a problem with the particularnebulization session or a pattern that has developed over time based onpast nebulization sessions for the particular user. Based on data fromthe one or more sensors in the smart nebulizer, the remote server maygenerate alerts to send via text, email or other electroniccommunication medium to the user's physician or other caregiver.

Referring to FIG. 105, one embodiment of a smart nebulizer system isshown as including a nebulizer 10 and a controller 340 with a pluralityof sensors (referred to in some embodiments as detectors) (shown in oneembodiment as three 310, 320, 330) providing inputs to the controller.The sensors 310, 320, 330 may be embodied, or take the form of, varioussensors or detectors disclosed hereinafter. In one embodiment, thesensor 310 detects pressure and flow rates of compressed air enteringthe nebulizer, the sensor 320 detects aerosol generation, for exampleactivation/actuation detection, and the sensor 330 detects inhalationand exhalation flow, breathing patterns and flow rates, with specificembodiments of each of these sensors described for example and withoutlimitation below. Additional sensors for medicine identification,concentration identification, particle size measurement, fill/residualvolume determination and end of treatment may also be incorporated intothe system, as hereinafter described below. The system also includes afeedback component 350, which may include for example and withoutlimitation, a visual, audible or haptic feedback component, orcombinations thereof, including for example a display (user interface),speaker and vibratory component.

In order to calculate the respirable dose (m_(respirable)), the systemneeds input as to the total mass (m_(total)) delivered and therespirable fraction (RF).M _(respirable)[μg]=m _(total)[μg]×RF[%]

Using a nebulizer with a consistent mass output rate [μg/min] for agiven flow rate allows the system to make an assumption that the totalmass output is equal to the total inspiratory time multiplied by thetotal mass output rate multiplied by a multiplication factor, k1, basedon the average inhalation flow rate. The purpose of the multiplicationfactor is to account for the varying drug output and respirablefraction, based on the inhalation flow rate.m _(total)[μg]=k1×m _(rate)[μg/min]×t _(inspiratory)[min]

However, the output rate and the respirable fraction depend on thepressure and flowrate of the compressed air. Therefore, both the outputrate and respirable fraction need to be expressed in terms of the inputflowrate and pressure. These relationships may be empirically calculatedand categorized according to nebulizer type. For example, the outputrate of one nebulizer may be take the form of:m _(rate) =k2×Q _(input) +k3×P _(input) +C

Where k2 and k3 are multiplication factors, Q_(input) is the input flow,P_(input) is the input pressure and C is an offset constant.

Referring to FIG. 105, sensor 310 senses the pressure and flowrate ofthe compressed air source and determines the output rate, which is usedto calculate the total output, and the respirable fraction (RF), both ofwhich are required to calculate the respirable dose.

Another variable required to calculate the respirable dose is the totaltime during which the patient/user is inhaling and the nebulizer isgenerating aerosol. The total time can be determined by calculating theduration of overlapping time that sensors 320 and 330 are detectingaerosol and inhalation, respectively.

Layered on top of this are the performance differences of differentmedications in the nebulizer system. A stored database of medicationsprovides the necessary performance characteristics of each medicationwith the nebulizer. In one embodiment, the patient/user manually entersthe medication information, for example by a smart device application,in wireless communication with the nebulizer system.

The smart nebulizer also provides a mechanism for improving inhalationtechnique through coaching and feedback. Proper breathing techniques,especially inhalation, can optimize drug delivery to the lower airways.Too forceful an inhalation can result in impaction of even respirableparticles in the upper airways. Real time feedback of inhalation flowrate allows the smart nebulizer to provide a breathing coach that guidesthe breathing cycle of the user/patient to ensure they receive an idealdosage of medication.

For example, as shown in FIG. 107, the feedback, e.g., visual display,may be configured as a game. In one embodiment, the bird 380 representsthe inhalation flow rate, which must pass through the pipes 382 withoutgoing outside the limits (upper and lower) 384, 386.

Referring to FIG. 106, a smart nebulizer flow chart is shown. Once thesystem has detected that treatment has started, for example by sensingan activation/actuation detection, a flow from one or more sensors, orby pushing a start or on button, inputs from sensors 310, 320, 330, orother sensors disclosed hereinafter, are monitored and the datacaptured. If inhalation ceases for a predetermined period of time, thesystem will timeout and return to standby. If inhalation is detected,but the input compressed airflow is not correct, an error will begenerated. If inhalation is detected and the input airflow is correct,but the nebulizer is not generating aerosol, the system will indicatethe end of treatment and calculate the respirable dose and log thetreatment data.

If inhalation is detected, the input airflow is correct, and aerosol isbeing generated, the system will provide real-time feedback via afeedback device about the user's inhalation flow rate and/or end oftreatment in order to improve technique. This feedback can take severalforms including visual (see e.g., FIG. 107), audible and haptic. Thefeedback may be provide a visual interface, an audible or vibratorywarning if the inhalation flow rate is above or below a certain range.The feedback device may also provide a visual, audible or vibratoryfeedback indicia that the end of treatment has been reached. Acting onthis feedback, the user/patient is able to control/adjust theirinhalation flow rate and maintain that flow rate within an acceptablerange, thereby maximizing their respirable dose.

When the nebulizer system has determined that the user has stopped usingthe nebulizer, the nebulizer system stores the treatment data locally,or transmits the data for storage on a separate device. The data may beviewed at a later time/date by the user or healthcare provider to tracktreatment adherence. Various feature, together with their respectivetechnical requirements, are listed in Table 1, together with the valueadded to the nebulizer system.

TABLE 1 FEATURES, TECHNICAL REQUIREMENTS AND VALUE ADDED Value AddedFeature Technical Requirements Adherence/Compliance Breath CounterIdentification of start and end of breathing Identify when the devicehas cycle, record/track cycles been used (date/time) and for BreathingPattern Monitor Measure and record flow measurements how long and/orprompt over the course of treatment(s) patient of treatment ActuationIdentify movement of actuator Recognition/Counter Treatment Log Manualentry into app/webpage of drug type, fill volume, concentration orautomatic recognition of this information. Historical display oftreatment log. Treatment Time Identification of start and end oftreatment - ex. full fill volume to sputter Treatment Reminder Softwareand GUI for setting reminders - displayed on device, app, SMS, emailCorrect/Efficient Use Breathing Pattern Monitor Measure and record flowmeasurements Proper use of the device over the course of treatment(s)Treatment Time Identification of start and end of treatment - ex. fullfill volume to sputter Posture Coach Identify patient and deviceorientation and provide real time feedback. App based or printed IFU.Breathing Coach Identification of breathing pattern and real timeadaptive feedback/instructions, IFU instructions. Could be made into agame Environmental Monitor Measure the environment the device is beingused/stored in (temperature, humidity, pressure) - ensure device isbeing used within proper operating conditions Treatment CompletionBreath Counter Identification of start and end of breathingAwareness/Dose cycle, record/track cycles Assurance Breathing PatternMonitor Measure and record flow measurements Identifying when treatmentover the course of treatment(s) has been completed and Breathing CoachIdentification of breathing pattern and real notifying the patient timeadaptive feedback/instructions, IFU instructions. Could be made into agame Dose Delivery Rate Measure the quantity of drug passing into theuser's mouth per unit of time Residual Dose Measure the residual volumein the device after treatment Inlet Pressure Measure and record inletpressure, use in estimation of drug output Treatment Time Identificationof start and end of treatment - ex. full fill volume to sputter DosageAwareness/Control Breathing Coach Identification of breathing patternand real Provide information on how to time adaptivefeedback/instructions, IFU use the device for different instructions.May include game durations/breaths depending Dose Delivery Rate Measurethe quantity of drug passing into on drug and concentration the user'smouth per unit of time Residual Dose Measure the residual volume in thedevice after treatment Treatment Time Identification of start and end oftreatment - ex. full fill volume to sputter Titration (Dose Delivered)Calculate the mass of the drug delivered to the patient EfficiencyBreathing Coach Identification of breathing pattern and realAwareness/Encouragement time adaptive feedback/instructions, IFUPositive feedback to promote instructions. May be incorporated into afaster treatments game Efficacy Awareness Spirometry Measure flow rates,time, pressure. Real time measure of lung Training required to interprethealth or risk of exacerbation results/complicated algorithm andestablishment of Analysis of Exhaled Breath Collection of exhaled air(cooling required) baseline health metrics Condensate Device StatusAwareness Dose Delivery Rate Measure the quantity of drug passing intoIdentify when device has the user's mouth per unit of time - exceededusable life and/or deterioration over time should be replaced InternalNebulizer Pressure Measure pressure inside device to provide informationon leakages and compressor status Expiry Date Reminder Identification offirst use and number of treatments completed/time elapsed since firstuse Environmental Monitor Measure the environment the device is beingused/stored in (temperature, humidity, pressure) - recognize if storageconditions are exceeded Hygiene/Safety Environmental Monitor Measure theenvironment the device is Awareness being used/stored in (temperature,Reality or perception humidity, pressure) - determine if proper ofimproved hygiene cleaning has been achieved Cleaning ReminderRecognition of the number of treatments completed and prompt user thatcleaning is required and cleaning method recommended Sustainability/Disposal Prompt/Instructions Recognize end-of-life and prompt user toResponsibility Awareness for Disposal (after expirary dispose of productand provide proper Provide information on proper date is reached - appbased) instructions for disposal. disposalActivation Detection

In order for the system to be able to track dosage delivered to thepatient and determine when the end of treatment has been reached, thenebulizer system identifies when the device has activated and aerosol isbeing produced. Knowing the duration of activation, in conjunction withknown performance characteristics of the nebulizer, the delivered dosagemay be tracked over time and end of treatment calculated. In a BANdevice, aerosol is generated when the actuator moves from the OFFposition to the ON position and aerosol is drawn up the liquid channelsand impacts on the primary baffle to generate aerosol. In some BANdevices, e.g., the AEROECLIPSE nebulizer, a manual override button maybe manually depressed to produce aerosol, or a mode selector dial may beactuated to position or configure the nebulizer in a continuous mode,where aerosol is produced continuously. It would be advantageous, butnot necessary, if a smart nebulizer system can differentiate between aBAN device or mode and a continuous delivery device or mode, as each ofthese scenarios can affect the dosage that is delivered to the patient.The movement of the actuator, audible cues, pressure characteristics,transmissibility through aerosol flow, temperature and humidityvariations in the presence of aerosol, capacitance and inductance canall be used, but are not limited, to determining when the nebulizer hasbeen activated and deactivated.

Sound-Based Approach Sensor in Device

Referring to FIGS. 14-16, in a sound based approach, microphone(s) 102,104 are used to “listen” for audible cues that indicate activation hasoccurred and aerosol is being generated. Many time and frequency domainmethods are available that may be used to analyze the signal provided bythe microphone. A sound-based approach has the added benefit of beingable to differentiate when the nebulizer is being run dry (e.g., whenpatient practices breathing technique prior to filling the medicationbowl).

There is an audible difference in a device that is being run dry and onethat is aerosolizing fluid. In addition, a microphone can be used tolisten for sputter, an indication that treatment has been completed.Prior to actuation, comipressed air is flowing through the device. Onactuation, liquid is drawn up the liquid channel and strikes thebaffle/diverter, creating an audible cue that actuation has occurred. Asecond microphone may be used to measure background signal and noiselevel. The noise or sound level(s) may be recorded over time. Themicrophone may also record deactivation.

In all sound-based approaches, it should be understood that the role ofthe microphone 102, 104 may not be limited to listening for activationand deactivation but may also be used to record background noise and tocancel out this noise from inside the system so as to help determinewhich signals indicate activation has occurred. An example of this wouldbe an algorithm used in many noise cancelling headphones where anexternal microphone provides a reference noise signal and the systemswill add the signal of the same amplitude but inverted phase to thesignal originating from inside the system as destructive interference.

External Microphone

In one embodiment of a smart nebulizer system, an external microphone102 is used to “listen” to the nebulizer. In this application themicrophone can be a standalone part that is separate from the nebulizeritself or it can be the microphone from a phone that is placed near thepatient to record sounds that occur during the treatment and displayinformation to the patient using an app based interface.

Light-Based Methods

Light Transmission—Actuator

Referring to FIG. 26, in a light transmission activation detectionset-up, a light detector 106 is positioned opposite a light source 108with an air gap separating them. In one embodiment, the gap between thelight source and the detector is unobstructed when an opaque actuator 22is in the OFF position. Movement of the actuator 22 breaks the air gapbetween the light source and sensor and changes the output from thelight detector, indicating the actuator has travelled sufficiently togenerate aerosol. In another embodiment, the air gap between the lightsource and light detector is obstructed by the actuator in the OFFposition. When the actuator moves into the ON position, the gap is nolonger impeded and the signal from the sensor changes. This is notlimited to the visual spectrum of light. In one embodiment, infrared isused so that it is not visible by the patient.

Light Transmission—Aerosol

Referring to FIGS. 27A and B, as stated previously, in a lighttransmission method there is an air gap between the light source 108 anddetector 106 and changes in the signal from the light sensor indicatethat activation has occurred. In an aerosol based trigger, the lightsource and sensor are positioned such that the air gap between them isin an aerosol or flow pathway 112, for example in the mouthpiece 12 orchamber 14, and production of aerosol will disrupt the light due toscattering by the aerosol particles. This will reduce the light detectedby the sensor, indicating that activation has occurred. This is notlimited to the visual spectrum of light and may use multiplewavelengths. In one embodiment, infrared is used so that it is notvisible by the patient.

Light Reflectance

Referring to FIGS. 28A and B, in a light reflectance embodiment, a lightsensor 110 and light source 108 are located along the aerosol pathway112. The components are isolated from each other and placed adjacent toeach other such that, when the nebulizer is not activated and no aerosolis being produced, limited light is detected by the sensor due tolimited reflectance by the opposite face of the device. In the presenceof aerosol, there is increased reflection due to the close proximity tothe adjacent light source and sensor which produces a measurabledifference in the intensity of the light detected by the sensor. This isnot limited to the visual spectrum of light and may use multiplewavelengths. In one embodiment, infrared is used so that it is notvisible by the patient.

Colour Reflection

Also referring to FIGS. 28A and B, a white light source 108 ispositioned adjacent to a detector 110 capable of identifying the colourspectrum of the detected light. The components are placed in the aerosolpathway such that on activation, aerosol is drawn in front of thecomponents, such that the presence of the aerosol particles causes lightto be reflected back at the sensor. In the presence of aerosol, theaerosol will absorb certain wavelengths of light thus changing thewavelengths that are free to pass back to the sensor. A change in thewavelengths detected by the sensor indicates that aerosol is present,and may identify the medication that is being aerosolized and theconcentration thereof.

Acceleration

Referring to FIGS. 17 and 18, in one embodiment of the breath actuatednebulizer, the actuator 22 moves between OFF and ON positions inresponse to inhalation sufficient to overcome the positive pressurewithin the device. An accelerometer 116 placed within or on the actuator22 could be used to measure the movement of the actuator and duration atwhich it accelerates. The area under the generated acceleration versustime curve may then be used to determine the change in velocity andtotal displacement of the actuator. Determination of activation is notlimited to calculating displacement of the actuator and other algorithmsmay be used to accomplish the same task, such as the acceleration oninhalation and sudden deceleration when the actuator bottoms out on thenozzle cover. To improve the accuracy of an accelerometer basedactivation detection method, a second accelerometer may 118 be used toserve as a baseline or frame of reference for the actuator movement. Thesecond accelerometer would be placed in a portion of the nebulizer thatis stationary in relation to the rest of the device and does not move inresponse to inhalation and exhalation flows (ex. placed within themouthpiece 12, on retainer 16, top, bottom, etc.). By doing so, motionartifacts caused by the movement of the patient holding the device willnot trigger a “false positive” activation detection as bothaccelerometers should register similar accelerations and the differencebetween them will be approximately zero. As the accelerometers 116, 118are placed in separate components with the processing unit ideallylocated with the stationary accelerometer, a wired or wirelesscommunication system may interface between the devices. In a wiredconnection embodiment, a single power supply may be used, while awireless system embodiment may require multiple power supplies for thesensors.

Pressure

Absolute Pressure

Referring to FIGS. 10-12, breath actuated nebulizers 10 are configuredwith a component 120 that responds to changing pressure within thedevice caused by inhalation and exhalation by the patient. Whenconnected to a compressor, or positive pressure air supply, a positivepressure within the device pushes up on a biasing element/diaphragm 20and maintains the actuator into the OFF position. When the patientinhales through the device, thereby causing the pressure within thedevice to become sufficiently negative to pull the actuator into the ONposition, aerosol is generated. A pressure sensor 120 placed within thedevice, for example within the flow path 112 of the mouthpiece 12 canmeasure the pressure relative to atmospheric conditions (using a sensor122) and identify when activation has occurred, based upon knownpressure characteristics of the nebulizer on inhalation. As shown inFIG. 10, graphs of pressure and flow profiles are illustrated, with theactuation determined based on the measured pressures. A second pressuresensor 122 may be mounted exteriorly of the device, for example on theretainer or mouthpiece, to provide a reference data point foratmospheric pressure. A simple threshold analysis can be used to comparethe current pressure reading with a minimum pressure required toactivate the device.

The pressure sensors may provide information for determining breathingpatterns, and the monitoring thereof. When connected to the mouthpiece,the sensor(s) 120, 122 may be removed with the mouthpiece so that thereset of the device may be cleaned. For example, as shown in FIG. 12,the sensor 120, 122 may be mounted with a printed circuit board 124 onthe top or bottom of the mouthpiece in a location that is not disruptiveof the oral interface with the user.

Another approach is to analyze the pressure profile within thenebulizer. The pressure curve of the system over the course of abreathing cycle is characteristic of the nebulizer device and respondsto the movement of the inhalation and exhalation valves. Using thisknown characteristic profile and targeting the region that signals thatactivation has occurred, a signal originating from a pressure sensor 120within the nebulizer system can be compared to a target signal, in boththe time and frequency domain. This includes, but is not limited to,thresholds, autoeorrelation, minimization of root-mean squares andspectral coherence. Multiple analysis techniques can be used together toimprove the accuracy of the algorithm.

Strain Gauge

Referring to FIGS. 7-9, in one embodiment of a breath actuatednebulizer, the diaphragm 20 reacts to changing pressures within thedevice to move the actuator from an OFF to an ON position. As such,there is a minimum strain experienced by the diaphragm 20 as theactuator 22 is moved and bottomed out on the nozzle cover 34. A straingauge 128 may be applied to the flexible biasing element of thenebulizer, with the impedance of the gauge changing in response tochanging pressures within the nebulizer. One embodiment of such a devicewould involve the printing of a circuit on the surface of the diaphragm20. When strained, the circuit pathways becomes stretched and narrower,resulting in a higher resistance. Conversely, when compressed thecircuit becomes shorter and wider, lowering the resistance. Anotherembodiment of this system may have a separate flex sensor/strain gauge130 whose movement is driven by the movement of the diaphragm 20 oractuator 22, accomplishing the same function as a strain gauge printedon the surface of the diaphragm. A simple threshold algorithm would berequired to determine when sufficient strain on the diaphragm hasoccurred to move the actuator to the ON position. The amount of strainexperienced by the gauge is related to the pressure experienced withinthe device and the flow rates generated by the user. In addition, theinitial strain experienced by the diaphragm is indicative of the airsupply pressure (compressor versus central wall air) and may be used incalculating the dose delivered.

Physical Switch

Single Pole, Single Throw (SPST) Switch

Referring to FIGS. 103A-104B, in a SPST switch embodiment, a movingelement in the nebulizer, such as the actuator 22 or diaphragm 20, isused to close or open a switch. In a normally “off” switch embodiment,the actuator 22 and the hood seat of the nozzle cover 34 form a singlepole, single throw switch 132. An electrical power supply is connectedto a conductive path that is discontinuous in the area of the hood seaton the nozzle cover. The bottom surface 134 of the hood of the actuatorcontains a conductive path that bridges the discontinuous section 136 onthe nozzle cover, completing the circuit and signaling that activationhas occurred. When the nebulizer deactivates the circuit becomesdiscontinuous. A microcontroller is used to monitor the state of theswitch.

As shown in FIGS. 104A and B, in a normally “on” switch embodiment, theinner surface 138 of the dial contains a conductive path that extendsdown the legs of the dial to where they meet the diaphragm. A conductivepath 140 is printed onto the surface of the diaphragm 20 that connectsthe contact points of the dial legs. The path does not continue up theramps that the legs move over when switched to continuous mode. When thenebulizer is off, the circuit is continuous. On inhalation the diaphragm20 moves in response to the negative pressure inside the nebulizer andbreaks the circuit. Conversely, when the dial 142 is rotated tocontinuous mode, the legs move over the ramps of the diaphragm which donot contain a conductive path. A microcontroller monitors the state ofthe switch to determine when activation or deactivation occurs.

It is important to note that while the two embodiments described in thissection use existing components of the nebulizer to create a switch, anadditional component may be added to the nebulizer that responds toinhalation and exhalation flows to indicate when activation anddeactivation occurs. In addition, the method may be extended furtherthan the two embodiments listed and may be expanded to include anynormally on or normally off switch that changes state in response toactivation or deactivation of the nebulizer. The embodiments used inthis section were included for illustration purposes and show how such amethod may be implemented.

Reed Switch

Referring to FIGS. 101A and B, in a reed switch embodiment, a magneticcomponent 144 is made to be movable relative to a stationary surface. Asthe magnetic element is displaced it changes the state of a reed switch146 from ON to OFF or OFF to ON, indicating that activation ordeactivation has occurred. In one embodiment, the dome of the actuator22 is made of a magnetic material, and defines the magnetic component144, and a reed switch is incorporated into the retainer 16. When theactuator has moved sufficiently, it changes the state of the reedswitch, which is recognized by a microcontroller 148 and activationlogged. When the actuator 22 moves back to its initial position, thereed switch 146 moves back to its initial state and the microcontroller148 recognizes that deactivation has occurred. It is important to notethat placement of the reed switch and the magnetic component are notlimited to this one embodiment. Rather, the reed switch detectsactuation and/or deactivation of the nebulizer and the embodimentdescribed was for illustration purposes only.

Inductive Proximity Sensor/Switch

Referring to FIGS. 22A-23B, in one embodiment, a conductive element 150is built into the moving component of the nebulizer, such as but notlimited to, the dome of the actuator 22. A corresponding coil 152 isplaced around or near the path that the component moves in, such as theinner diameter of the dial. On inhalation, the moving component(actuator) 22 moves from the OFF position to the ON position, bringingthe conductive element 150 of the moving component closer to the coil152 or loop of the stationary component of the nebulizer. High frequencycurrent is passed though the coil 152 or loop to create an electricfield. When the conductive element of the moving component is broughtcloser or farther away from the loop there is a measurable change inimpedance in the coil 152 or loop. This change in impedance can signalwhen activation has occurred. This feature and principle may be appliedto any of the movable components within the nebulizer.

Capacitance Switch

Referring to FIGS. 24 and 25, a capacitance switch/proximity sensor 154may also be used to determine when activation has occurred. Two parallelplates 156, 158 are positioned such that one plate is placed on a“stationary” component of the nebulizer (does not move in response tothe breathing cycle) and one plate is placed on a movable component,such as the actuator or diaphragm. The capacitance between parallelplates 156, 158 is dependent on the permittivity of the free space (d),dielectric constant of the material in the gap, overlapping area of theplates and the distance between the plates. If the plates are positionedin an area where the overlapping area of the plates, permittivity of thefree space and dielectric constant of the material in the gap are fixedthen the changing capacitance is due to the changing distance betweenthe plates. In one embodiment two plates are separated by an air gap.One plate forms a ring around the underside of the dial/retainer whilethe other plate form a ring on the top surface of the diaphragm,opposite the plate on the dial/retainer. In response to inhalation flowthe distance between the plates increases and the capacitance changes.Knowing the relationship between the capacitance and distance allows youto determine the distance the actuator is from the dial, thus if theactuator has travelled sufficiently to produce aerosol. Since thedielectric constant of the material in the air gap is preferablymaintained as unchanging, the air gap preferably is not located in theaerosol pathway. Capacitance can be monitored with an oscillator orcharge/discharge circuit and changes in frequency indicate aerosolgeneration has occurred or stopped.

In another embodiment shown in FIG. 25, the distance between the plates156, 158, the permittivity of the free space and the dielectric constantof the material between the two plates is held constant and theoverlapping area of the two plates is varied. One plate is located inthe dome of the actuator while the other plate is located in thestationary retainer or dial. On inhalation, the overlapping area of thetwo plates increases or decreases, depending on their initialpositioning. Since the actuator moves axially in the nebulizer, thedistance between the plates would remain constant and only theoverlapping area would change thus changing the capacitance. Since thedielectric constant of the material in the air gap is preferablymaintained as unchanging, the air gap preferably is not located in theaerosol pathway. Capacitance can be monitored with an oscillator orcharge/discharge circuit and changes in frequency indicate aerosolgeneration has occurred or stopped.

Hall Effect

Referring to FIGS. 102A and B, a Hall Effect element 160 may be used tomeasure the activation and deactivation of the nebulizer. Hall Effectelements work by measuring the voltage of a Hall Effect element,perpendicular to the direction of current flow across the element. Inthe presence of a magnetic field, a voltage is induced across theelement, proportional to the field strength. In one embodiment, a HallEffect sensor 160 is mounted on the retainer 16 while the dome of theactuator contains a magnetic feature 144. On inhalation, the movement ofthe actuator 22 may be monitored by a microcontroller 148 measuring thetransverse voltage of the Hall Effect element as the proximity of themagnetic dome to the sensor will change the output voltage. When avoltage threshold has been reached the microcontroller can signal thatactivation has occurred as the actuator has moved sufficiently togenerate aerosol. Though this embodiment describes the movement of theactuator bringing the magnet closer to the Hall Effect sensor, anembodiment in which the magnetic component moves away from the sensor oninhalation would also be suitable. Also, the placement of the HallEffect sensor and magnetic feature are not limited to the retainer andactuator and any Hall Effect element may be used to measure activationand deactivation.

Force Sensing Baffle

Referring to FIGS. 83 and 84, in one embodiment, a force or pressuresensing element 162 is incorporated into the baffle 165. When theactuator is in the OFF position, a reduced flow of air strikes thebaffle as a portion of the flow escapes through vacuum break windows inthe nozzle cover 34. When the actuator 22 is down, all air flow isdirected at the baffle 165 as the windows in the nozzle cover areblocked as well as entrained air through the bottom opening of thenozzle cover. This force increases further when liquid is pulled throughthe liquid channel and strikes the baffle. This force/pressure readingmay be recorded by the sensing element 162 and monitored by a controlunit, with an increase over a certain threshold indicating aerosolformation, as shown in FIG. 84 for each of the air flow/actuator up,actuator down/no liquid and liquid striking baffle. This embodiment iscapable of being able to differentiate between the patient practicingproper breathing technique while the device is being run dry and whenaerosol is being produced.

Humidity

Referring to FIGS. 19 and 20, in one embodiment, a humidity sensor 166is placed within the nebulizer, in the aerosol pathway 112. One possiblelocation is within the mouthpiece 12 due to its proximity to the patent.Prior to aerosol generation pressured air from a central sir supply orcompressor is moving past the sensor. On activation, aerosol generatedwithin the device is collected by compressed and entrained air and flowsalong the inhalation pathway towards the patient. The air becomessaturated with the liquid droplets of the aerosolized medication andregisters as an increase in humidity when it flows past the sensor. Whenthe device deactivates, aerosol generation will cease and the compressedand entrained air flowing past the sensor is no longer saturated withwater vapor. With an embodiment such as this, the sensor 166 ispreferably calibrated before each treatment for the relative humidity ofthe environment it is being used in and the source of the compressedair. This calibration could be performed using a second, externalhumidity sensor. A minimum humidity change in a predefined period oftime could be used to detect activation and deactivation however manydetection algorithms can be used.

Temperature

Referring to FIGS. 13A-E, in one embodiment, a temperature sensor 168 isplaced within the nebulizer, in the aerosol pathway 112. The temperaturesensor 168 can determine if device is being supplied with compressed airas the flow of air over the temperature sensor will produce a measurabledecrease in temperature when compared to stagnant air. This can be usedto “wake” the device from a sleep or low power mode. When the actuatormoves into the ON position and aerosol flows along the inhalationpathway (FIG. 13B) there is a decrease in temperature as particles aredeposited on the sensor and evaporate. This further decrease intemperature indicates activation has occurred and a continued decreasedtemperature level signals the duration of aerosol production.

Deactivation can occur in two ways. The first scenario is when thepatient exhales through the device (FIG. 13C). This creates positivepressure within the device and the actuator moves to the OFF position.An increase in temperature is experienced due to the cessation ofaerosol and the warm, humid air from the patient's lungs passing thesensor. This indicates that activation has stopped. In the secondscenario (FIG. 13D), the patient removes their mouth from the mouthpieceto exhale and the lack of a negative, inhalation flow allows theactuator to move back to the OFF position. As before, the lack ofaerosol depositing and evaporating off the sensor registers as anincreased temperature increase and the system recognizes thatdeactivation has occurred.

Though the above embodiment describes the pressure sensor being placeddirectly in the aerosol pathway, the pressure sensor may also be placedelsewhere on the device and measure the local temperature changes.Multiple temperature sensors 168, 170 (see FIG. 13E) may be used tomeasure relative temperature changes to the external environment inorder to improve the accuracy of the system and set referencetemperatures.

Capacitance—Dielectric Constant of Aerosol

Referring to FIG. 21, assuming the dielectric constant of the aerosol isdifferent than that of air, a capacitive sensing method can be used todetermine when activation has occurred. A capacitor 154 can be createdby separating two conductive materials 156, 158 by an insulating airgap, for example in a flwo pathway 112 of a mouthpiece 12. The air gapis situated such that on aerosol production, aerosol flows through thegap. If the aerosol does have a different dielectric constant than airthan the presence of aerosol between the conductive change will resultin a measurable change in capacitance. Capacitance can be monitored withan oscillator or charge/discharge circuit and changes in frequencyindicate aerosol generation has occurred or stopped.

Flow

Measuring the flow through the device is not a direct method ofdetermining when activation takes place but using known performancecharacteristics of the device, such as the known flow to actuate,actuation may be registered. Measuring flow is also important formonitoring of the breathing pattern of the patient over the course ofthe treatment. As such, all embodiments and methods covered in the nextsection, Measuring Flow, are also applicable in determining whenactivation has occurred.

It is important to note that the various embodiments and methodsdisclosed herein may be combined to register actuation. Indeed,combinations of any of these techniques is contemplated as the differentembodiments/techniques can be linked together to improve the accuracyand expand the capability of the nebulizer system.

Measuring Flow/Breathing Pattern

It would be advantageous for a smart nebulizer to be able to monitor theinhalation and exhalation of the patient over the course of theirtreatment. Proper breathing techniques, especially inhalation, canoptimize drug delivery to the lower airways. Too forceful of aninhalation can result in impaction of even respirable particles in theupper airways. Real time feedback of inhalation flow rate would allowthe smart nebulizer system to provide a breathing coach feature thatguides the breathing cycle of the patient/user to ensure that thepatient/user receives the ideal dosage. Various electronic devices areavailable for measuring flow, including internal sensors that may beplaced within the nebulizer, external sensors and standalone devicesthat are capable of interpreting operating characteristics of thenebulizer and relating these signals into the flow through the device.The breath monitoring embodiment and method may be adaptable and able todetermine flow when used with a variety of air supply sources at varyingpressures. The breath monitoring embodiment is preferably robust enoughto reject environmental noise and isolate the signal of interest.

Sound Based Approach

Intrinsic Sound

Referring to FIGS. 29 and 30, a microphone 104 may be used to measurethe intrinsic sounds produced by the device when flow is moving throughit. The airflow pathway 112 within the nebulizer is often purposelytorturous to control the aerosol particle size. This creates turbulentflow that must pass around complex, blunt geometry. With an increasedflow there is a corresponding increase in the turbulence experienced anda change in the intrinsic sounds produced by the device. A microphonemay be placed within the device, on the outer surface or as a standalonesensor to detect the sound caused by the airflow through the nebulizer.Through experimental testing the relationship between the detected soundand flow rate can be determined. Many signal processing and analysistechniques are available to relate the microphone data to flow such as asimple volume threshold to more complex frequency domain analysistechniques. The sound is not limited to that which is detectable by thehuman ear and a wide frequency band can be used.

The intrinsic sound based flow measurement techniques are not limited tousing a single microphone and multiple microphones 102, 104 can be usedto improve the accuracy of the flow measurement as well as to captureenvironmental noise.

Generated Sounds

Referring to FIG. 31, much like an intrinsic sound approach, a singlemicrophone 104 or multiple microphones are used to detect soundspurposely produced by the nebulizer using special geometry 170 thatemits a sound when airflow passes over it, much like the FLOWSIGNAL flowindicator in the AEROCHAMBER aerosol holding chamber. In one embodiment,sound producing geometry 170 such as a reed is placed in front of theinhalation windows 172 of the nebulizer. Alternatively, the soundproducing geometry is molded into the inhalation window itself. Oninhalation, air is drawn through the sound producing geometry andproduces a known sound. The volume change or frequency shift caused by avarying flow rate can be recognized by the sound sensing unit of thenebulizer system and related to flow rate. A similar component can beadded to the exhalation ports to recognize exhalation flow rates. Themeasurement of flow using generated sound is not limited to placement atthe inhalation and exhalation windows and can be placed anywhere withinthe device that is in the inhalation and exhalation pathway. Differenttones may be produced for each flow path in order to distinguishinhalation and exhalation flows. As with the intrinsic sounds methods,the generated noise is not limited to the audible range of humans.

Doppler

Referring to FIG. 32, the Doppler Effect may be used to measure thevelocity (and flow rate) of passing particles in the nebulizer. Atransmitter and receiver unit 174, 176 are placed such that in thepresence of aerosol the sound produced by the transmitter is reflectedback at the receiver. This can be achieved by directing the transmitterand receiver at an angle to the flow path. Due to the velocity of theaerosol that is reflecting the sound, there is a shift in the frequencyin the received sound. If the particles are moving opposite thedirection of the transmitted sound, the reflected sound wave will bemore compressed and therefore at a higher frequency. The level of thefrequency shift can be related to the velocity of the particles. Knowingthe cross sectional area of the gas flow allows for the calculation offlow rate using the velocity. This method works for flows in bothdirections except the received sound will have a lower frequency thanthe transmitted wave. It is important to note that this method requiresthe presence of aerosol to act as a reflecting agent. As such, thismethod may also be used to detect activation but may be unable todetermine the flow rate of the dry air in the nebulizer prior toactivation.

In one embodiment, the transmitting and receiving components are placedadjacent to each other on the wall of the mouthpiece. The transmitterand receiver are angled so that the signal is projected at an anglealong the flow pathway and is not emitting perpendicular to the flow.This method is not limited to any one frequency range though it is oftenused with ultrasonic signals.

Time of Flight/Transit Time

Referring to FIG. 33, in a time of flight or transit time flowmeasurement embodiment, two transmitter and receiver components 174, 176are placed on opposing faces of a cylindrical element through which airflows. The sensors are placed at an angle Θ to the flow pathway witheach transmitter/receiver of each component facing the other. In oneembodiment this cylindrical element would be the mouthpiece. Sound isemitted by each component during opposing time intervals and the time ittakes for the sound to reach the opposing sensor is calculated. Knowingthe time of flight between the sensors in both directions gives anaverage velocity of the flow that is independent of the gas or particlespassing through the air channel. Knowing the geometry of the nebulizerand the velocity allows for a calculation of the flow rate.

Pressure Based Approach

Pressure Relative to Atmospheric

Referring to FIG. 34, in one embodiment a pressure sensor 120 is placedwithin the device to measure the internal pressure. The sensor must beplaced inside the closed system formed when the patient places theirmouth on the mouthpiece. This is the region that changes pressure inresponse to the patient's breathing, for example in the mouthpiece 12.On inhalation the internal pressure of the nebulizer becomes negativerelative to atmosphere and flow is drawn through the inhalation valveand into the patient's lungs. With increasing flow also comes a greatervacuum as flow of air into the nebulizer is limited by the inhalationvalves restricting the inhalation ports. As a result, increasing airflowrequires greater effort by the patient. On exhalation the pressurewithin the nebulizer becomes positive and increases with increasingexhalation flow as exit from the device is limited by the size of theexhalation ports and the valves covering them. A relationship existsbetween the internal pressure and flow rate though it is marginallydependent on the characteristics of each valve and possible leakages inthe nebulizer. A second pressure sensor 124 may be included to measureatmospheric pressure and results in a more robust design that is capableof accurate internal pressure measurement, independent of the externalenvironment.

Venturi

Referring to FIG. 35, the Venturi Effect can be used to measure flow bycreating a Venturi tube 180 within the nebulizer that forces a pressuredrop in an area with known geometry. A cylindrical tube is created thathas a smooth transition from one diameter to another with known crosssectional areas. Assuming the flow is steady state and laminar, and thatthe compression of the gas is minimal, conservation of mass requiresthat the velocity must change to maintain the same flow rate. Based onthe Bernoulli equation this creates a local pressure drop. The pressuredrop can be measured and the flow rate calculated.

A Venturi geometry is incorporated into a portion of the nebulizer suchas the mouthpiece 12 as shown in FIG. 36 to create a measurable pressuredrop that is recorded as a differential pressure. The disadvantage ofthis method is the narrowing of the mouthpiece accelerates the aerosoland provides them with more momentum, potentially increasing impactionin the upper airways.

Alternatively, a bypass Venturi tube 182, as shown in FIG. 37, iscreated off of the main airflow pathway that a portion of the flowsmoves through. The flow through this portion of the mouthpiece iscorrelated to the flow of air through the main body. The mouthpieceincludes the basic geometry of a cylinder transitioning to a smallerdiameter, and may create a measurable localized pressure drop for thisembodiment.

Pitot Static Tube

Referring to FIG. 38, in a pitot static tube embodiment, an area ofstagnation is created in the flow path typically using a cylindricalshaped geometry 184 with one closed end. The open end of the cylindricaltube faces the incoming flow. A pair of tubes 184 may face in oppositedirections. A pressure sensor 186 is placed within the tube usually onthe inner side of the closed face. In the presence of airflow a portionof the flow enters the tube and stagnates, building up pressure withinthe tube. With greater flows rates there is an increased pressure withinthe tube as the air experiences a greater deceleration and imparts moreforce on the sensor. This pressure profile can be characterized thoughtesting and a relationship between the pressure in the pitot static tubeand flow created. A second sensor may also be placed to measureatmospheric pressure for reference and calibration purposes.

In one embodiment, two pitot static tubes may be placed in themouthpiece, with the tubes facing in opposite directions of flow. Oninhalation, one Pilot tube will experience an increase in pressure whilethe other would see no change or a small decrease in pressure. Thisembodiment has the advantage of not only measuring flow but also thedirection of flow within the nebulizer.

Restricted Orifice

Referring to FIGS. 39 and 40, similar to the Venturi tube, a restrictedorifice method of measuring flow uses a change in cross sectional areato force a measurable pressure drop. Unlike the Venturi embodiment, therestricted orifice 188 is an abrupt change in cross sectional area whichallows for a greater change in pressure. However, the restricted orificeresults in greater acceleration of the aerosol and disturbs the flowpath. In addition, the abrupt change in cross sectional area mayincrease the impaction of the aerosol. Unlike the Venturi flowmeasurement, the restricted orifice provides a bidirectional pressuremeasurement. The restrictive orifice is positioned between thepatient/user 183 and any valving or leaks such that it is measuring flowinto and out of the patient's lungs.

As shown in FIG. 40, the user 183 has positioned the mouthpiece in theiroral cavity. It should be understood that the same depiction applies toall other embodiments disclosed herein, meaning those embodiments arealso positioned in the user's mouth during use.

Wedge Flow Measurement

Referring to FIGS. 41 and 42, while similar to the restricted orificeembodiment, one side of the flow path is restricted with a triangularshaped cross-section, or wedge 190, for example within a cylindricalshaped flow path of the mouthpiece 112. The cross section creates alower pressure differential then a restricted orifice and thereforedisrupts the flow less. This embodiment is applicable to air flow thathas a low Reynolds number (laminar flow). As with the restrictedorifice, this embodiment provides a bidirectional method of measuringflow. In one embodiment, the flow restriction is placed within themouthpiece having a cylindrical shape, in part because the flow is theleast turbulent at this point in the nebulizer.

Light Based Methods

Reflectance—Internal

Referring to FIG. 43, a light source 108 and sensor 106 can be placedadjacent to one another but separated by opaque material such that nodirect light from the light source can reach the sensor. The source andsensor are both directed in the same direction towards a component ofthe nebulizer that moves in response to flow and the degree to which themember moves is dependent upon the flow rate. For illustration purposes,an embodiment that uses the existing inhalation and exhalation valves192, 194 will be described. When the patent is not breathing through thedevice the valves are closed and much of the light is reflected off ofthe valve and back to the light sensor. On inhalation the inhalationvalves 192 curl in response to the flow and some light is allowed topass through the inhalation windows while some is still reflected backto the sensor. As inhalation flow increases so too does the curl angleof the valve and less light is reflected back to the light sensor. Thesame process happens on exhalation as the exhalation vales 194 movesaway from the valve seat with exhalation flow. A relationship may bedetermined between flow and the intensity of light received by eachlight sensor. This embodiment has the benefit of being able to determinethe direction of flow as a reduced reflectance from the inhalation valveindicates inhalation flow and vice versa. This embodiment and method isnot exclusive to the existing inhalation and exhalation vales and may beexpanded to any component that moves in response to flow and whosedegree of movement is dependent upon the flow rate. This embodiment andmethod is applicable to all wavelengths of light and all filteringmethods.

Shine Through

Referring to FIGS. 45A and B, a light source 108 and sensor 106 areplaced on opposite sides of a component 192 that moves in response toflow and restricts the intensity of light that reaches the sensor. Thelight source can be ambient or generated by a source such as an LED. Itis also applicable to all wavelengths of light and is not restricted tothe visible spectrum. With increasing flow there is an increasing degreeof movement by the moveable component. This allows for increased amountof light to pass through to the sensor. A relationship may be determinedbetween the light intensity registered by the light sensor and the flowrate. As described with respect to the Reflectance—Internal embodiment,one embodiment uses the existing inhalation and exhalation valves (FIG.46) with a light sensor placed opposite the valves such that oninhalation and exhalation the movement of the valves allow light to passthrough to the light sensor.

Oscillating Member

Referring to FIGS. 47A-C, an opaque oscillating component 200 is placedwithin the flow path 112 with a light source 108 and sensor 106 oneither side. When there is flow present the oscillating component movesat a frequency that is unique to the flow rate. The oscillation of thecomponent periodically blocks the path between the light source andsensor. The frequency at which it does so can be related to flow rate. Avibrating element such as a reed 200 could be used (with the reed 200 inone embodiment moving side-to-side (FIG. 47B), or a rotary component 202(FIG. 47C) such as a pinwheel. However, this embodiment/method is notlimited to these two oscillating components, but rather is applicable toany component that moves at a set frequency in the presence of flow andperiodically blocks the transmission of light to a sensor.

Temperature Based Methods

Hot Wire Anemometer

Referring to FIG. 48, a wire 204 is heated electronically and placedwithin the flow path 112. As air flows past the wire 204, the wire iscooled and the resistance of the wire changes. The circuitry used tomeasure the temperature change can be constant current, constant voltageor a pulse-width modulation configuration. All methods effectivelymeasure the temperature change and may be related to the air flowthrough experimentation. This embodiment may include any thermistor orthermocouple that is positioned internally in the device.

Thin Film Thermal Sensor

Referring to FIGS. 49A and B, a thin film sensor 206 is placed on theinternal or external surface of the device (not in the flow path), forexample on the outside of the bottom housing 14. When air is flowing inthe nebulizer it cools the surfaces of the device and as in the Hot WireAnemometer configuration, causes a measurable change in resistance inthe sensor which may be monitored by, but not exclusively, amicrocontroller 148. This embodiment should take into account that thetemperature of the nebulizer is also related to the presence of aerosol,and that the response time may be slower as the thermal transfer mustoccur in the body of the device for the temperature change to bedetected by a thin film placed on its surface.

Strain/Flex Sensor

Deflection

Referring to FIG. 50, air flowing past an element 208 in the airflowpathway 112 exerts a force on the element. Increases in airflow alsoincrease the force exerted as the particles experience a greaterdeceleration when they strike which is directly related to the forcethey exert. By placing a flex sensor 208 in the airflow path it ispossible to calculate the air flow rate based on the level of thedeflection of the flex sensor. The level of deflection is related toflow rate through experimentation.

This may also be applied to the existing inhalation and exhalationvalves, which respond to inhalation and exhalation flows, with theirlevel of deflection related to the flow entering or exiting thenebulizer. A strain gauge may be printed on the existing valve surfacesto measure their level of deflection which can then be related to flow.Alternatively, the existing valves themselves could be replaced withflex sensors that control the rate and direction of flow.

The flex sensor may be resistance based or made of piezoelectricmaterial. In a resistance based embodiment the deflection of the sensorcauses a change in resistance that may be monitored by a control unitusing a variety of methods. In a piezoelectric embodiment the deflectionof the sensor creates a voltage that is proportional to the amount ofdeflection.

Strain on Diaphragm

Referring to FIGS. 51A and B, in one embodiment, one or multiple straingauges 128 are integrated into the biasing element 20, e.g., diaphragm,of the nebulizer to measure the strain experienced by the flexiblematerial. The biasing element may be a spring geometry formed by thesilicone diaphragm. On inhalation the diaphragm 20 responds to changesin internal pressure and is pulled down in order to activate theactuator. With increasing inhalation airflow there is an increase in thevacuum pressure and even though the position of the actuator isrestrained by the nozzle cover, the diaphragm is continually pulled downand strained further. The level of strain experienced may be related tothe inhalation flow rate. On exhalation there is a buildup of positivepressure within the device which also strains the diaphragm and may berelated to the exhalation flow rate. Using this embodiment inconjunction with activation/deactivation detection would allow thenebulizer system to determine flow rate and the direction of flow.

Oscillating

Referring to FIGS. 52 and 53, an oscillating component 210 is placed inthe air flow pathway 112 that will oscillate at a frequency that isproportional to the flow rate. The component may be composed of aresistive flex sensor that changes impedance on deflection or apiezoelectric material that generates a voltage on deflection. Thefrequency of the oscillation may be monitored by a control unit that canrelate the frequency to flow rate through a relationship determinedthrough experimentation.

Turbine Flowmeter

Referring to FIG. 54, a rotor or pinwheel 212 is placed within the flowpath 112. Flow causes the rotor or pinwheel to rotate at a frequencythat is related to the flow rate. Rotational speed of the turbine can bemeasured with many methods such as through Hall Effect elements todetect the passing rotor blades, a contact switch or the breaking of alight curtain. It is important to note that determining the rotationalspeed of the turbine is not limited to the methods listed here. Thismethod is advantageous as it does not cause a significant pressure drop.However, placing a turbine in the aerosol pathway may increase aerosolimpaction and reduce drug output.

Displacement

Referring to FIG. 55, all methods of measuring displacement have atleast two common elements: (1) a stationary component 212 that does notresponds to inhalation and exhalation flow; and (2) a moveable component214 that moves in one axis on inhalation and exhalation. Variousembodiments may include a third element: (3) a connecting componentconnecting the stationary and movable components, such as a spring 216(linear or non-linear) that returns the movable component to a steadystate position when there is no air flow. On inhalation the flow of airmoves the movable component relative to the stationary one. A greaterflow rate produces a greater displacement as the airflow experiencesgreat deceleration when it strikes the movable component, thus exertinga greater force. The configuration may allow for unidirectional orbidirectional movement depending on the type of spring used which wouldallow for one configuration to be able to measure both inhalation andexhalation flow rate. As shown in FIG. 61, the displacement ispreferably measured in a region 228 between the user/patient and anydeviations in the airflow pathway, for example in the mouthpiece.

In various embodiments, disclosed below, the displacement flow ratemeasurement techniques rely on a measurement of local flow, and aretypically positioned between the oral interface and any deviations inthe airflow pathway. Leaks and exhalation and inhalation pathways areexamples of these deviations. By placing the sensing unit in this area,the airflow experienced by the patient can be measured directly. Thesensing element may be placed elsewhere in the nebulizer system, howeverthere no longer is a direct measurement of the flow experienced by thepatient.

Hall Effect

Referring to FIG. 56, a Hall Effect sensor 212 is at a stationaryposition and the movable component 214 is comprised of magneticmaterial. A spring 216 connects the two components. On inhalation theflow exerts a force on the magnetic element and moves it closer to theHall element, and produces a change in the magnetic field that ismeasurable. This change may be related to the displacement of themagnetic component and thus the air flow. On exhalation the elementmoves further away from the Hall element. Though the embodiment abovedescribes the magnetic element moving closer on inhalation and furtheron exhalation, the opposite orientation would accomplish the same task.

Capacitance

Referring to FIG. 57, a capacitance switch/proximity sensor method mayalso be used to determine the displacement of the movable component inrelation to the stationary one. Two parallel plates 212, 214 arepositioned such that one plate 212 is placed on a “stationary” componentof the nebulizer (does not move in response to the breathing cycle) andone plate 214 on a movable component with the two plates connected by anon-conductive biasing element such as a spring 216. The capacitancebetween parallel plates is dependent on the permittivity of the freespace, dielectric constant of the material in the gap, overlapping areaof the plates and the distance between the plates. If the plates arepositioned in an area where the overlapping area of the plates,permittivity of the free space and dielectric constant of the materialin the gap are fixed then the changing capacitance is due to thechanging distance between the plates which is related to the air flow.As with the Hall Effect embodiment this may measure both inhalation andexhalation flow using a single configuration though multiple may be usedif more appropriate. This embodiment is preferably used when thedielectric constant of the material in the air gap is unchanging, suchthat the air gap preferably is not located in the aerosol pathway or thespace between the plates is shielded from the aerosol. Capacitance canbe monitored with an oscillator or charge/discharge circuit and changesin frequency indicate the flow rate.

Inductance

Referring to FIG. 58, a conductive element is built into the movingcomponent 214 of the displacement sensor. A corresponding coil 212 isplaced around or near the path that the component moves in and isstationary relative to the rest of the nebulizer system. Alternatively,the coil could be moving and the conductive element is stationary. Oninhalation, the moving component moves relative to the stationary one.High frequency current is passed though the loop to create an electricfield. When the conductive element of the moving component is broughtcloser or farther away from the loop there is a measurable change inimpedance in the loop. This change in impedance is directly related tothe displacement of the sensor. This, in turn, is related to flow rate.

Reed Switches

Referring to FIGS. 59 and 60, for a reed switch embodiment, a magneticcomponent 218 is made to be movable relative to a stationary surface 220and connected by a biasing element 216. As the magnetic element isdisplaced it changes the state of a series 222 of reed switches 224positioned such that the activation or deactivation of switches may berelated to the displacement of the movable element. This principle canbe applied to any number of reed switches and can be applied to amagnetic element that either activates or deactivates the switches. Thisdisplacement may then be related to the flow rate.

Potentiometer

Referring to FIG. 60, a movable component 226 is connected to apotentiometer such that on displacement of the movable element itchanges the impedance of the potentiometer. Resistance may be monitoredusing a simple Wheatstone bridge circuit and microcontroller. Note thatmonitoring of the impedance is not limited to this basic circuit.

Vibration/Acceleration

Referring to FIGS. 62 and 63, similar to a sound based approach, thetorturous flow within the nebulizer, designed to generate particles of arespirable size, creates turbulence as the airflow is forced aroundirregular, blunt geometry. The air flow and aerosol particles strikingthese surfaces exert a force on the nebulizer and cause the device tovibrate at very low amplitude, high frequency, levels. By placing anaccelerometer 230 on the surface of the device it is possible to measurethis vibration. This idea is expandable to one (1), two (2) and three(3) axes accelerometers. A microcontroller 148 would sample the datafrom the accelerometers and perform an analysis of it. This analysiscould be programmed into the microcontroller or transmitted to anexternal unit with greater processing power. The signal may be analyzedby a number of methods in both the time and frequency domain to detectpatterns in the acceleration that could be related to the airflowthrough the device. The accelerometer may record acceleration caused bythe movement of the device by the patient, otherwise known as motionartifacts. Typically motion artifacts are low frequency and can beremoved using a high pass filter. It is expected that the vibrationcaused by the airflow to be of a higher frequency and may be separatedfrom the motion artifacts in the frequency domain.

This embodiment may be expanded to include measurement of accelerationgenerated by an oscillating component. Much like the generated soundmethod described previously, a component may be added that oscillates ata frequency that is proportional to the flow rate passing over it.Unlike the sound method, the oscillating component does not produce asound but the oscillation is transferred to the device or to theaccelerometer directly to measure the magnitude and frequency of thevibration. This, in turn, may be related to flow.

Air Supply Pressure and Nozzle Flow

Referring to FIGS. 64 and 65, determining the pressure and airflow thatis being supplied to the device is important in accurate calculation ofdrug output and delivery rate. The two parameters cannot be separated asthey both contribute to the drug output rate and particle size. Wall orcentral air supplies used by hospital are generally capable ofdelivering 50 psi. However, various nebulizers may provide instructionsdirecting the user or caregiver to dial down the pressure until the flowis between 7 and 8 L/min. Nebulizers may also be configured to work withnebulizer compressors 236, including the Trudell Medical InternationalOMBRA Table Top and Portable compressors. With these supply components,it may not be necessary to reduce the pressure or flow, as they areconfigured to operate at their maximum performance. Differences innozzle flow between devices operating on the same compressor are due tovariations in the nozzle orifice size and flash. Knowing both thepressure and flow is important as particle size is dependent upon theenergy supplied by the compressed air supply. In a situation where thecompressors have the same nozzle flow but one has a higher pressure, thehigher pressure compressor can potentially produce finer particles, allother factors held equal, as it has more energy to transfer to theliquid to increase the surface area (droplet formation).

Nozzle pressure and flow may be measured directly or inferred. Directmeasurement in line with the compressed air supply and the nozzleorifice may be used or measurements may be taken elsewhere in thenebulizer system that are relatable to the air supply pressure and flow.

Embodiments and methods that measure pressure directly are preferablyconfigured to not cause a significant permanent loss in pressure,especially in nebulizers that operate using a compressor well below the50 [psi] maximum operating pressure.

Direct Pressure Measurement

Absolute or Relative to Atmosphere

Referring to FIGS. 66 and 67, as described in Pressure BasedApproach—Flow Measurement a pressure sensor 232 may be placed in-linewith the air supply, e.g., tube 234, to the nebulizer and measure theabsolute pressure within the device or the with the addition of a secondsensor 236 to atmosphere, then the pressure relative to atmosphere. Thepressure sensor is not limited to placement within the nozzle and mayalso be placed within the tubing 234 itself.

Strain Gauge

Referring to FIG. 68, a strain gauge 128 placed on a flexible hosing 234used to transport the compressed air supply could be used to determinethe pressure supplied to the nebulizer. In one embodiment the straingauge is placed on the tubing used to connect the nebulizer to the wallair or compressor. When the tubing is pressurized it is placed intension and expands. This expansion can be measured with a strain gaugeand communicated to a control unit through physical or wirelesscommunication.

Direct Flow Measurement

Pressure

All flow measurement techniques covered in the Measuring Flow—PressureBased Approach section are applicable as an in-line flow measurementtechnique however all of them result in various degrees of permanentpressure loss which should be avoided. This method is also able toprovide absolute pressure by monitoring the downstream pressure sensorreading or the pressure relative to atmosphere through the addition of athird sensor exposed to the external environment.

Sound

The Measuring Flow—Time of Flight/Transit Time applies to measuring theair flow applied to the nebulizer. The sensors may be placed anywherebetween the tubing attachment and exit orifice of the nebulizer.

Temperature

The Measuring Flow—Temperature Based Methods applies to measuring theair flow applied to the nebulizer. The sensors may be placed anywherebetween the tubing attachment and exit orifice of the nebulizer.

Turbine

The Measuring Flow—Turbine Flowmeter applies to measuring the air flowexiting the pressurized gas orifice of the nebulizer. The sensor may beplaced anywhere between the tubing attachment and exit orifice of thenebulizer however this method may result in a permanent pressure loss.

Inferential Pressure/Flow Measurement

Inferential pressure and flow calculations are not able to providedirect measurements of pressure or flow but they may be inferred if thecalculation error introduced through the range of pressure and flowcombinations is not statistically significant. Inferential measurementsof pressure and flow are not able to distinguish between pressure andflow as these parameters cannot be separated from one another withoutdirect measurement of each. As such, only pressure will be referred toin the following methods as it is the driver of the flow. Fluctuationsin flow at constant pressure are the result of variations in thepressured gas orifice dimensions and the level of flash present.

Intrinsic Sound

When supplied with pressurized air and being run dry, the nebulizerproduces a sound that is characteristic of the pressurized gas exitingthe orifice. As with flow measurement using sound, the sound isdependent on the flow exiting the orifice and the subsequent turbulencecaused by the air following the tortuous pathway in the device. Anincrease in pressure produces an audible increase in sound intensity andmay affect the frequency content of the sound. A single or multiplemicrophones may be used to monitor the sound and of the nebulizer beforetreatment is administered to establish the pressure/flow from the airsupply. Multiple analysis techniques exist that can analyze the soundusing a local control unit or a remote control unit to which data iswirelessly communicated and compared to a known library of soundprofiles with known performance characteristics.

Vibration/Acceleration

As with Vibration/Acceleration—Flow Measurements, an accelerometer maybe used to measure vibration of the nebulizer prior to aerosolization.These vibrations may provide an indication of the pressure/flow beingsupplied to the nebulizer with each pressure/flow having acharacteristic acceleration signature. The Vibration/Acceleration—FlowMeasurements section above provides more details on the implementationof such an embodiment and method.

Flow Through Device

All embodiments and methods described in the Measuring Flow/BreathingPattern section may be used to measure the pressure/flow being suppliedto the nebulizer. Flow measurements taken while the device is being rundry without the patient interfacing with the device are indicative ofthe pressure/flow supplied to the nebulizer. Local measurements ofpressure and flow may be related to the flow through the pressurized gasorifice through experimental testing. These flow measurements may thenbe compared to a database of supplied pressures/flows and theircorresponding local flow measurement.

Force of Air Striking Baffle

In one embodiment, the baffle is constructed from a load cell. Whenpressurized air is supplied to the nebulizer it exits the pressurizedgas orifice and strikes the baffle, exerting a force on it proportionalto the flow rate. A control unit can monitor this force calculate thepressure/flow supplied to the device through a relationship determinedexperimentally. Additionally, this system may be used to wake a controlunit from a low energy state as pressurized gas must be supplied to thenebulizer for treatment to occur. This would reduce energy requirementsof the system and, if the unit is battery powered, help to prolong thebattery life. A pressure sensitive sensor may also be used in place of aload cell.

Compatible Smart Compressor

An alternative approach to having the smart nebulizer system monitoringthe air supply pressure and flow is to market a series of compressorsthat are compatible with the smart nebulizer. These compressors monitorthe supply pressure and flow through a variety of means and communicatethis data to the nebulizer. This data may be transmitted wirelesslydirectly to the nebulizer or to the overall control unit, such as asmartphone. The data could also be transmitted through a physicalconnection such as a data cable ran through the oxygen tubing or byplacing the nebulizer is a port on the compressor for data syncing.Please note that the data transmission is not limited to these methods.

Medication Identification

A smart nebulizer system should be able to recognize the medicationbeing administered to the patient. This information is important to thepatient, healthcare provider and insurer as it ensures the treatmentregime is being adhered to. In addition, knowing the medication beingnebulized is also important in calculating the respirable fraction.Though many of the medications commonly nebulized are a solution andyield comparable particle sizes, some medications have differentphysical properties such as viscosity that affect the particle size thenebulizer is capable of generating. Medication identification can beaccomplished in a variety of ways ranging from identification based onthe packaging to a chemical analysis of the medication. Each of theindividual methods listed below may be used to identify the medication,or a combination of the methods may be used to increase the robustnessof the medication identification feature.

Image Processing

Existing Packaging Barcode

Referring to FIG. 76, some medication packaging 240 (boxes and nebules)have existing barcodes 238 that may be read by a bar code scanner. Thebar code scanner may be incorporated into the smart nebulizer 10 itself,into to a phone based application that is in communication with thesmart nebulizer, or a standalone reader that can communicate with thesmart nebulizer system, for example by bluetooth,

Supplied Barcode

Similar to Existing Packaging Barcode except a specialized barcode maybe placed on the medication by the user, distributor or manufacturerrather than relying on existing ones. This embodiment and method ensuresany medication that is provided with this barcode has been pre-approvedfor use.

Text Recognition

Text recognition software can recognize the text written on themedication packaging and identify the applicable information.

Feature Recognition

An image of the packaging is compared to image kernels in a database ofcompatible medication. The correlation coefficient between the capturedimage and all image kernels may be calculated and medication identifiedbased on the greatest correlation coefficient. Other matching algorithmsare available and may be used.

QR Code

This method is similar to Supplied Barcode except that a QR code is usedin place of the barcode.

RFID or NFC Device

Referring to FIGS. 77 and 78, Radio Frequency Identification (RFID) tags242 or other Near Field Communication (NFC) components may be applied orbuilt into the medication packaging 240. The identification component242 may be recognized by a reader 244 on the smart nebulizer 10 itselfor a standalone device that is in communication with the smartnebulizer. Alternatively, many smartphones have NFC capability builtinto them. These phones may be used to recognize the medication andcommunicate with the nebulizer.

Access Patient Electronic Medical Records (EMR)

Referring to FIG. 78, a patient's Electronic Medical Records (EMRs) maybe accessed by the smart nebulizer system through direct Wi-Fi access orwireless communication with an Internet accessible device. If thepatient has been prescribed multiple medications for nebulization it cansupply a subset of medications that another identification method mayselect from.

Manually Selected by the User

Rather than automatically detecting the medication being used by thepatient, the user may manually input the medication they are using. Thismay be done on the device itself or on a standalone device that is incommunication with the smart nebulizer. There are many methods thepatient may use to input their medication such as a drop down list orsearchable database. Alternatively, a chat bot may be used. This uses anautomated assistant that asks the patient a series of questions using achat window type interface and the patient is able to respond usingnatural language, eliminating the need to navigate a user interface.

Capacitance

Two oppositely charged features are separated by an air gap. Onactivation, aerosol flows through the gap. Assuming the aerosols havedifferent dielectric constants from each other, the capacitance changecaused by the aerosol in the air gap can be measured and compared to adatabase of capacitance values of compatible aerosols. Alternatively, asshown in FIG. 71, the two oppositely charged features 246, 248 may beplaced on either side of the medicine howl, or reservoir, such that whenmedication is inserted into the nebulizer the medication fills the spacebetween them. Assuming the dielectric constants of the medications aremeasurably different, the medication may be identified. The capacitiveprobe may also be placed directly within the liquid medication.

Single Drug Nebulizer

Rather than identifying the drug used in the nebulizer, the nebulizerscan be programed with the information pertaining to a single drug and bemarketed for use solely with that drug. To reduce the risk of thenebulizer being used with multiple drugs it could be a single use devicethat may come pre-filled with medication and has no port through whichadditional medication may be easily inserted. The electronic portion ofthe nebulizer would be removable and each use, the disposable portion ofthe nebulizer would be discarded. Information pertaining to the drug inthe nebulizer could be programmed into a low cost component such as, butnot limited to, an EEPROM chip and accessible by the reusable portion ofthe nebulizer when docked.

Spectroscopic Drug ID/Colour

Referring to FIGS. 79-80B, single or multiple wavelength spectroscopycould be used to analyze the aerosol or liquid medication to determinethe chemical structure of it. All chemicals absorb unique wavelengths oflight and the degree to which they absorb the light is dependent on thebonds present in their chemical structure. A light source 108 of asingle or multiple wavelengths may be shone through the aerosol orliquid medication and the absorbency analyzed by a detector placedopposite the light source. The absorbency information may then becompared to a database of compatible medication. The light source anddetector may be placed anywhere along the aerosol pathway, such aswithin the mouthpiece (FIG. 80B) or within the medication bowl (FIG.80A) for analysis of the liquid. This is, in effect, an analysis of thecolour of the medication, however colour is the measure of what isreflected by the substance rather than absorbency.

pH

Referring to FIG. 82, the pH of each medication may be used to helpidentify the medication or be used to select a subset of medicationsfrom which another identification method may select from. Nebulizedmedications are often pH adjusted in order to balance them to be closeto neutral however differences still do exist between medications. Anexample of this would be differentiating between Acetylcysteine andAlbuterol. Assuming a medication has been narrowed down to these twomedications through another method, pH could be used to differentiatethem as Acetylcysteine solutions have pH ranging from 6.0 to 7.5 whileAlbuterol solutions are typically between 3.0 and 5.0.

In one embodiment a pH sensor 250 is placed in the medication bowl 46where it is in contact with the liquid. The sensor is able to measurethe pH of the liquid due to the differences in hydrogen ionconcentration. The sensor communicates this to a microcontroller whichmay select the medication or a subset of medication from a database ofpH readings and medications, determined experimentally.

Concentration Identification

It would be advantageous if a smart nebulizer could measure theconcentration of medication in the medication bowl at any point in time.Identification of the medication does not provide concentration, knowingthe concentration is required in order to calculate drug output. Even ifmedication concentration is obtained when the medication is identified,it is normal for the concentration of medication in the bowl to increaseover the course of a treatment and drug output rate to increase as aresult. The following methods may or may not be used in conjunction withthe medication identification methods described previously.

Capacitance

Referring to FIG. 97, assuming the medication has already beenidentified, the particular capacitance of the medication at a point intime may be relatable to the concentration. If the capacitance hasalready been identified, the initial concentration may be measurablefrom the initial capacitance. It is assumed that the dielectricproperties of the medication are different than the aqueous mixture theyare diluted with. As a nebulizer treatment progresses and the drugbecomes more concentrated in the nebulizer bowl, there may be a changein the overall dielectric constant due to the greater concentration ofthe medication. This may be measured by insulated parallel features thatare oppositely charged. A charge discharge circuit may be used to testthe capacitance and be monitored by a microcontroller. In oneembodiment, a capacitance probe is integrated into the lowermost sectionof the nozzle and nozzle cover with the outer surface of the nozzle andinner surface of the nozzle cover acting as the oppositely chargedfeatures. The gap between them is positioned such that it is alwaysbelow the level of the fluid and the distance between them isunchanging. A separate capacitive probe could also be integrated intothe bottom surface of the medication howl. The probes are preferablyimmersed in the medication as the presence of air between the oppositelycharged features may affect the capacitance.

Spectroscopy/Colour

Referring to FIG. 99, as with medication identification usingspectroscopy/colour, single or multiple wavelength spectroscopy could beused to analyze the liquid to determine the chemical structure of it aswell as the relative concentration of each component. All chemicalsabsorb light to one degree or another and the degree to which theyabsorb them is dependent on the bonds present in their chemicalstructure. A light source of a single or multiple wavelengths may beshone through the liquid medication and the absorbency analyzed by adetector placed opposite the light source. The absorbency informationmay then be compared to a database of compatible medication. The lightsource and detector may be placed within the medication bowl such thatliquid is able to pass between them when present. The concentration ofeach compound should be reflected in the relative absorbencymeasurements with more concentrated compounds able to absorb more light.This is, in effect, an analysis of the colour of the medication, howevercolour is the measure of what is reflected by the medication rather thanwhat is absorbed.

Light Transmission

Referring to FIG. 86, similar to the spectroscopy/colour techniqueexcept the relative intensity of light that transmits through the liquidis analyzed rather than a detailed analysis of the detected wavelengthsand level of absorption. In one embodiment, a light transmissiondevice/method may look solely at infrared transmission as it would notbe visible by the patient. A sensor 262 may be positioned below atransparent/translucent bowl, with a light source 264 positioned in thebowl, with the light passing through the liquid.

Conductivity

Referring to FIG. 100, conductivity may also be used to measure theconcentration of the medication. Many nebulized medications use acidsand bases to balance the pH which introduces charged particles to theliquid. The number of these charged particles is directly related to theconductivity of the liquid, as a current can more easily conduct in thepresence of a greater number of charged particles. This is related tothe measurement of pH however it accounts for all ions in the medicationwhile pH is a measure of hydrogen ions only. Conductive sensors tend tomeasure conductivity through a capacitive change or an inductive change.Preferably, the active region of the sensor is placed within themedication bowl so that it is continually immersed in the liquidmedication.

pH

Referring to FIG. 85, if the concentration change of medication resultsin a change in the number of hydrogen ions in the medication than pH maybe related to the concentration. A pH probe 250 may be placed in themedication bowl in contact with the liquid and monitored by amicrocontroller 148. Note that this measurement cannot be used todetermine the initial concentration and can only measure a change inconcentration as most nebulizer medications are balanced through theaddition of acids and bases until the phis close to neutral.

Time of Flight

Referring to FIG. 98, if the medication is known, the concentration maybe identified based on the time of flight between a transducer 300 andreceiver 302. A probe 304 is placed in the medication bowl that containsa transducer and receiver that are directed at one another and separatedby an air gap. The probe is placed such that it is always immersed whenmedication is in the bowl. Air gaps between the transducer and receiverwould affect the accuracy of the measurements. Sound ways of theultrasonic frequency are often used by all frequencies are applicable tothis claim. The probe measures the time it takes for the sound to travelfrom the transducer to the receiver. The concentration of the medicationbetween the transducer and receiver may affect the speed of propagationof the sound wave. A microcontroller would monitor the time of flightand relate this to a concentration from a database of values determinedexperimentally.

Manual Entry

The initial medication concentration can be manually input into thenebulizer if it is known by the patient. This may be done on the deviceitself or on a standalone device that is capable of communicating withthe nebulizer. This embodiment and method may be particularly useful formedications where the concentration change or the duration of thetreatment is not substantial.

Particle Size Measurement

Particle size distribution is an important factor in calculating thedose delivered to the patient. This is because there is a respirablerange of particles between 0.4 [μm] to 4.7 [μm]. Particles below thisdiameter are too small to deposit in the airways and are lost throughexhalation while particles above this range impact in the upper airwaysas they have too much inertia to follow the convoluted pathway into thelower airways. Drug that impacts in the upper airways is not usable bythe patient. Dose delivered to the patient is the product of the drugoutput and the fraction of the particles within the respirable range,also known as the respirable fraction. It is possible to characterizethe particle size of the nebulizer based on the inlet pressure and flowas well as the inhalation flow rate and compile these relationships inan electronic database that is searchable by the smart nebulizer system.However, it would be advantageous to be able to directly measure theparticle size distribution of the aerosol directly within the nebulizerand not introduce another level of uncertainty into the dose deliverycalculation.

Light Diffraction Measurement

Referring to FIGS. 69 and 70, light diffraction measurement of particlesize distribution assumes particles are approximately spherical inshape. Monochromatic light, from a light source 266, which isapproximately collimated (parallel) is shone through the aerosol as itflows along the inhalation pathway. As the light shines across theaerosol pathway it may or may not pass through aerosol droplets thatdiffract the light. The angle of diffraction is dependent upon theparticle size with particles of equal size diffracting the lightequally. Opposite the light source 266, on the other side of the aerosolpathway is a Fourier lens 268 that separates the received light beams bythe angle of diffraction and focuses this light on a detector 270 behindit. Light passing through that is diffracted at the same angle will befocused on portions of the detector that are equidistance from thecenter of the detector. This creates a spatial separation of light basedon the angle at which it was diffracted by the aerosol. The pattern oflight intensity received by the detector is passed through to a controlunit for processing and compared to a database of light intensitypatterns with known particle size.

It is important that the set-up be positioned after all baffling as thisbaffling is responsible for producing the required particle sizes. Thetorturous path that the airway must follow causes most particles abovethe respirable range to impact on the internal walls of the device andrain out, back into the medicine bowl where it may be re-nebulized.

One embodiment integrates this particle measurement method into themouthpiece 12. On one side of the cylindrically shaped mouthpiece is alight source 266 while the other contains the Fourier lens 268 anddetector 270. A control unit 148 may also be contained in the mouthpieceto process the signals from the detector. Alternatively, the data may bewirelessly transmitted to an external device for processing, such as aphone. The system may be tied in with one of the activation detectionembodiments so that the light source and detectors only turn on whenaerosol is present. As aerosol passes through this area it creates aunique diffraction pattern that is spatially encoded by the Fourier lensonto the detector. The nebulizer can then take this data and determinethe percentage of aerosol that is in the respirable range. Thisembodiment could also be used to detect activation. Prior to aerosolproduction, no aerosol would be passing between the light source andlens and therefore, no light would be scattered and the Fourier lenswould focus all light on the DC, or low frequency, section of thedetector. On activation, the light would be scattered and focused toother portions of the detector, indicating that aerosol was present aswell as its particle size distribution.

Inertial Separation

Referring to FIGS. 71A-C, another option for measuring particle size isto mechanically separate the particles based on their size and analyzethe flow of these ordered particles past a sensor. Particles ofdifferent sizes have different masses. As the airflow forces the aerosolaround the baffling within the nebulizer every particle resists thechange in direction due to their inertial forces. Particles with largermass will resist the change in direction more than smaller ones due totheir greater inertial force. As a result, smaller particles are able toturn these corners more quickly than larger ones and particles may beseparated based on their trajectory. This method of inertial separationmay be done in a variety of ways using a multitude of geometries andflow paths such as through microfluidic channel and vortex separation,all of which are applicable to this embodiment.

In one embodiment, the existing geometry of the nebulizer is used. Asaerosol is produced, air enters through the compressed gas orifice andthe inhalation ports, collects aerosol formed by at the primary bafflingand moves around the secondary baffling, henceforth known as the fin280. As the airflow moves around the top edge of the fin 280 and towardsthe mouthpiece 12 it forces the airflow to make an approximately 180°directional change (FIG. 71B). The smaller particles are able to followthe contour of the fin while the inertia of the larger ones causes themto take wider trajectories. This creates a spatial separation of theparticles sizes into ‘bands” with the larger particles tending to becloser to the top half of the device and the smaller ones are lower,closer to the contour of the fin.

A light sensor 108 and detector 106, or an array/series thereof, may beplaced opposite of each other with this segregated airflow movingbetween them as shown in FIG. 72. The range of light intensitiesdetected by the opposing sensor, taking into consideration thedifferences in diffraction of particle sizes, could be related to theparticle size distribution. Multiple wavelengths of light sources anddetectors may be used for each “band” of particle size. By doing so,diffraction from one band of particles to another detector will not showas an increase in light intensity as the detector will not registerlight of a different wavelength. Image processing may also be used tolook at the relative “density” of the aerosol in each section of thegradient and estimate particle distribution based on this.Alternatively, the particles may be physically separated by guiding asubset of the flow through microfluidic channels and analyze each of thechannels separately for characteristics dependent on the amount ofaerosol in each channel such as, but not limited to, capacitance,inductance, conductivity, light transmission, light reflectance, pH,temperature and humidity.

Force Sensing Baffle

As described in Air Pressure and Nozzle Flow—Force of Air StrikingBaffle, a force or pressure sensing element is incorporated into thebaffle. Knowing the force of the aerosol striking the baffle would allowfor an estimation of the particle size. This embodiment and method mayaccount for factors such as nozzle misalignment and baffle variation andis a local measurement of the actual energy being applied to the mixedliquid flow to form aerosol.

End of Treatment

End of treatment can be defined in a number of ways. If the dosage isknown based on the respirable amount that must be delivered to thepatient, end of treatment can be calculated using a combination ofmethods covered previously. However, many treatment regimens do notprovide the respirable dosage for the patient and provide a treatmentprotocol based on time or sputter. In the United States, a HospitalProtocol Summary has been developed for the current AEROECLIPSEnebulizers. This protocol defines end of treatment based on a volume ofdrug nebulized until initial sputter is heard or a volume of drugnebulized for five (5) minutes. A smart nebulizer may be capable ofdetermining when sputter has occurred or an internal clock capable ofdetecting initial activation and counting down treatment time andsubsequently notifying the patient when the end of the timed treatmenthas been reached (see FIG. 73).

Sputter

Microphone

Referring to FIGS. 74-75B, in one embodiment, a microphone 120 is placedwithin the nebulizer to listen for sputter. Alternatively, a microphoneis placed externally or is contained in a separate, stand-alone device.Sputter is caused by gaps in fluid flow through the annular liquidchannels due to insufficient medication in the medication bowl. Thiscauses a rapid switching between the ON and OFF states. The ON state iswhen liquid is being drawn through the liquid channel and is impactingon the primary baffle while the OFF state is when no liquid is beingaerosolized and only air is striking the baffle. A control unit couldcompare the current state of the audio signal to known OFF and ONsignals in a database and recognize rapid switching between them. Therate at which the device switches between these states is important asit can differentiate between the activation and deactivation caused bythe breathing cycle and gaps in the liquid flow. This analysis is notlimited to the time domain and can be processed with alternativemethods, all of which are applicable to this embodiment. When thenebulizer recognizes that sputter has occurred it notifies the patient.

Force Sensing Baffle

As in Air Pressure and Nozzle Flow—Force of Air Striking Baffle, a forceor pressure-sensing element is incorporated into the baffle. When theactuator is in the OFF position, a reduced flow of air strikes thebaffle as much of the flow escapes through vacuum break windows in thenozzle cover. When the actuator is down, all air flow is directed at thebaffle as the windows in the nozzle cover are blocked and air isentrained due to the negative pressure over the liquid channel drawingadditional flow through the nozzle cover. This force increases furtherwhen liquid is pulled up the liquid channel and strikes the baffle.Sputter may be identified as the gaps in the liquid flow reducing theforce on the baffle and returning it to levels immediately prior toaerosol formation, but not the levels when the actuator is in the OFFposition. This would allow for differentiation between sputter andactivation/deactivation of the nebulizer. Alternatively, the rapidswitching between the ON and OFF states on sputter may differentiatefrom the relatively slow frequency of purposefulactivation/deactivation. When the nebulizer recognizes that sputter hasoccurs it notifies the patient.

Timed Treatment

In one embodiment, the control unit of the device has internal clockfunctions that can determine when a predetermined amount of time haselapsed. When used in conjunction with any method described in theActivation Detection section, activation of the device starts aninternal clock that records treatment duration. In the United States,this time is commonly five (5) minutes. At the end of the predeterminedamount of time the nebulizer notifies the patient that end of treatmenthas been reached.

Fill and Residual Volume Determination

It would be beneficial if a smart nebulizer was able to measure theinitial fill volume and/or residual volume of the medication. Though theinitial fill volume may be made available through the medicationidentification feature and residual volume estimated based on the drugoutput calculations, it would be advantageous to be able to measurethese parameters directly to remove a degree of uncertainty from thesystem. Residual volumes in particular are important as they representthe amount of drug that the nebulizer is not able to nebulize and istherefore wasted. Tracking this is important as it can potentiallyindicate the performance of the nebulizer. A high residual volume aftersputter could indicate a device has exceeded its useful life and shouldbe replaced. This ensures the patient is always receiving a consistentlevel of treatment. A high residual volume could also indicate that thedevice has been insufficiently cleaned and prompt the user to do so, aswell as providing proper instructions for them to follow. Trackingresidual volume is may also provide feedback to researchers and productdevelopers.

Fluid Level

Initial fill volume and residual volume may be estimated based on thefluid level in the medication bowl. Knowing the fluid level and thegeometry of the medication bowl allows for the calculation of the volumeof medication. The disadvantage of such a method is that it cannotaccount for medication that is coating the internal surfaces of thenebulizer and have not drained back into the medication bowl. Also,calculating fluid level requires the fluid surface to be relativelystill. This means that fluid level cannot be measured while the deviceis aerosolizing due to the turbulence that is created from thepressurized air as it is redirected radially by the primary baffle.

Thin Film Capacitance Sensor

Referring to FIG. 87A, a thin film, flexible capacitive sensor 280 couldbe placed on the outside side of the medication bowl to measure thefluid volume. As with other capacitive methods described in thisdocument, the dielectric constant of liquid is different than that ofair. The presence of liquid near the capacitive sensor causes a changein capacitance that may be measured and related to fluid level throughexperimentation. The greater the volume of liquid in the medicationbowl, the greater the area of the capacitive strip that is in closeproximity to the liquid and the greater the capacitance change. Theadvantage of this method is that the thin film, capacitive sensor may beplaced on the outside of the device and not in direct contact with thefluid.

Referring to FIG. 87C, another type of capacitive fluid level sensorinvolves a cylindrical shaped probe 288 with a cylindrical core inside,separated from the outer casing 290 by an annular air gap. These twoelements are oppositely charged to form a capacitor. When the probe isplaced into the medication, fluid is allowed to enter the bottom of theprobe and fill a portion of the air gap between the oppositely chargedprobe and outer casing. Since the dielectric constant of the fluidmedication will be different than that of air there will be a measurablecapacitance change. The degree of capacitance change is related to thelevel of the fluid in the probe.

Float

Referring to FIGS. 94 and 87B, a float based sensor can also be used tomeasure the volume of medication in the nebulizer. In a float sensorthere is always a floating element 286 that rests on the top surface ofthe fluid. Changes in the fluid level also change the position of thefloating element. The position of the float in relation to a stationarysensing unit 284 may be monitored using a multitude of methods and isrelated to the volume in the nebulizer based on the known geometry ofthe nebulizer bowl. The position of the floating element may be trackedby, but not limited to, resistance change of a potentiometer, capacitiveproximity sensing, inductive proximity sensing, hall effect, change instate of a series of reed switches and more. This embodiment isapplicable for all methods of measuring volume in the nebulizer using afloat based probe.

Pressure

Referring to FIG. 88, a pressure sensor 290 may be used to measure thevolume of fluid in the bowl. This method is effectively measuring theweight of the liquid above the pressure sensor. In one embodiment thepressure sensor is placed at the lowermost portion of the medicationbowl. On addition of liquid into the nebulizer, the pressure sensor iscovered by the liquid and registers an increase in pressure due to theweight of the liquid directly above it. As the medication is aerosolizedthe amount of liquid above the sensor decreases and the sensor registersa lower pressure. This method is not limited to the use of a singlesensor as an addition sensor may be added to monitor atmosphericpressure. As with the other fluid level measurements, this methodrequires the liquid to be still with an unmoving surface and is unableto account for liquid hang-ups on the internal surfaces of the device. Aload cell would accomplish the same task as the pressure sensor.

Permittivity of Light

Referring to FIG. 89, the fluid level may be estimated by evaluating thepermittivity of light through the liquid. A light source 108 may bepositioned above the maximum fluid level with a sensor 106 positioned atthe bottom of the bowl. Alternatively, the light source may be placedwithin the medication bowl and the sensor placed above the maximum fillmarker. In the absence of medication the sensor registers maximum lightintensity as light is able to travel from the source to sensor withminimal diffraction. On addition of the medication, light is refractedby the liquid and a lower intensity is registered. An increase in theamount of liquid between the source and sensor may decrease the lightintensity further and can be related to medication volumeexperimentally. This embodiment and method is not limited to using asingle wavelength or even by the visible spectrum.

Parallel Conductive Strips

Referring to FIG. 90, a number of parallel conductive strips 292 can beplaced on the internal surface of the medication bowl with knowndistances between each strip. A microcontroller can be used to monitorthe resistances between or to each conductive strip. If all conductivestrips are initially covered by the liquid there would be a lowresistance between different strips. As the liquid level lowers anduncovers a strip this will register as a high impedance, potentially anopen circuit, as the current can no longer easily flow back to ground.This will give an approximate fluid level height based on the number ofconductive strips that are exposed to and the known distances betweenstrips. In one embodiment, the conductive strips are placed tocorrespond with existing fill volume lines on the nebulizer.

Time of Flight

Referring to FIG. 91, a transducer and receiver 174, 176 may be placedabove the fluid such that on creation of a pulse, the pulse will reflectoff the fluid surface and back at the receiver. Based on the time ittake for the pulse to travel from the transducer, reflect off of thesurface and travel back to the receiver the distance of the sensors tothe fluid level can be calculated and the fluid level deduced from this.This method is not limited to ultrasonic waves and can use anyfrequency.

Image Processing

Referring to FIG. 92, an image of the fluid level relative to a knownmarker may be captured and analyzed by a microcontroller to determinethe fluid level in the nebulizer bowl. This can be done by counting thepixels between the marker and the fluid level or by comparing the imageto a database of images with known volumes and selecting the fluid levelwith the highest correlation coefficient. This is not limited to usingan internal camera 294 and an external camera such as a smartphones maybe used and the images communicated to the smart nebulizer.

Light Curtain

Referring to FIG. 93, as with Activation Detection using a lightcurtain, a single light source or multiple light sources 108 may beplaced such that multiple light detectors 106 are placed opposite ofthem with an air gap between them where medication fills. Similar to theLight Permittivity method, as fluid passes between the sensors and thelight source a reduced intensity of light is detected as more light isreflected or diffracted away from the sensor, By knowing the spacing ofthe detectors the fluid level may be estimated. Alternatively, multiplelight sources could be used and a single detector. When no medication isin the nebulizer a maximum light intensity is measured. As medicationcovers the light sources, less light is detected.

Weight of Device

Referring to FIG. 95, measuring the weight of the device with a scale298 is one way of determining the residual volume if the initial weightof the device is already known as well as the density of the medication.In most cases it may be acceptable to approximate the density to be thatof water. This method of determining residual volume is advantageous asit is not affected by the liquid hang-up within the device. In oneembodiment a scale is used to measure the device before medication isadded, after medication is added and after treatment is complete. Thescale could be a standalone device that is capable of communicating withthe smart nebulizer system. The measurement from the scale readout couldalso be manually input into the smart nebulizer system by the patient.In addition, many currently available smart phones have pressuresensitive displays that could calculate the weight of the nebulizerbased on the measured pressure and the surface area in contact with thescreen.

In another embodiment, shown in FIG. 96, a pressure sensitive surface orload cell 296 is incorporated into the bottom surface of the nebulizer.When the nebulizer is placed on a flat surface the sensors registers theweight of the nebulizer and communicates this information back to acentral control unit.

Communication and Data Processing

In order to provide faster and more accurate processing of the sensordata generated within the smart nebulizer, data may be wirelesslycommunicated to a smart phone, local computing device and/or remotecomputing device to interpret and act on the raw sensor data.

In one implementation, the smart nebulizer includes circuitry fortransmitting raw sensor data in real time to a local device, such as asmart phone. The smart phone may display graphics or instructions to theuser and implement processing software to interpret and act on the rawdata. The smart phone may include software that filters and processesthe raw sensor data and outputs the relevant status informationcontained in the raw sensor data to a display on the smart phone. Thesmart phone or other local computing device may alternatively use itslocal resources to contact a remote database or server to retrieveprocessing instructions or to forward the raw sensor data for remoteprocessing and interpretation, and to receive the processed andinterpreted sensor data back from the remote server for display to theuser or a caregiver that is with the user of the smart nebulizer.

In addition to simply presenting data, statistics or instructions on adisplay of the smart phone or other local computer in proximity of thesmart nebulizer, proactive operations relating to the smart nebulizermay be actively managed and controlled. For example, if the smart phoneor other local computer in proximity to the smart nebulizer determinesthat the sensor data indicates the end of treatment has been reached,the smart phone or other local computing device may communicate directlywith a pressurized gas line relay associated with the gas supply to thesmart nebulizer to shut down the supply of gas. Other variations arealso contemplated, for example where a remote server in communicationwith the smart phone, or in direct communication with the smartnebulizer via a communication network, can make the decision to shutdown the pressurized gas supply to the smart nebulizer when an end oftreatment status is determined.

In yet other implementations, real-time data gathered in the smartnebulizer and relayed via to the smart phone to the remote server maytrigger the remote server to track down and notify a physician orsupervising caregiver regarding a problem with the particularnebulization session or a pattern that has developed over time based onpast nebulization sessions for the particular user. Based on data fromthe one or more sensors in the smart nebulizer, the remote server maygenerate alerts to send via text, email or other electroniccommunication medium to the user's physician or other caregiver.

The electronic circuitry in the smart nebulizer, the local computingdevice and/or the remote server discussed above, may include some or allof the capabilities of a computer 500 in communication with a network526 and/or directly with other computers. As illustrated in FIG. 5, thecomputer 500 may include a processor 502, a storage device 516, adisplay or other output device 510, an input device 512, and a networkinterface device 520, all connected via a bus 508. The computer maycommunicate with the network The processor 502 represents a centralprocessing unit of any type of architecture, such as a CISC (ComplexInstruction Set Computing), RISC (Reduced Instruction Set Computing),VLIW (Very Long Instruction Word), or a hybrid architecture, althoughany appropriate processor may be used. The processor 502 executesinstructions and includes that portion of the computer 500 that controlsthe operation of the entire computer. Although not depicted in FIG. 6,the processor 502 typically includes a control unit that organizes dataand program storage in memory and transfers data and other informationbetween the various parts of the computer 500. The processor 502receives input data from the input device 512 and the network 526 readsand stores instructions (for example processor executable code) 524 anddata in the main memory 504, such as random access memory (RAM), staticmemory 506, such as read only memory (ROM), and the storage device 516.The processor 502 may present data to a user via the output device 510.

Although the computer 500 is shown to contain only a single processor502 and a single bus 508, the disclosed embodiment applies equally tocomputers that may have multiple processors and to computers that mayhave multiple busses with some or all performing different functions indifferent ways.

The storage device 516 represents one or more mechanisms for storingdata. For example, the storage device 516 may include a computerreadable medium 522 such as read-only memory (ROM), RAM, non-volatilestorage media, optical storage media, flash memory devices, and/or othermachine-readable media. In other embodiments, any appropriate type ofstorage device may be used. Although only one storage device 516 isshown, multiple storage devices and multiple types of storage devicesmay be present. Further, although the computer 500 is drawn to containthe storage device 516, it may be distributed across other computers,for example on a server.

The storage device 516 may include a controller (not shown) and acomputer readable medium 522 having instructions 524 capable of beingexecuted on the processor 502 to carry out the functions described abovewith reference to processing sensor data, displaying the sensor data orinstructions based on the sensor data, controlling aspects of the smartnebulizer to alter its operation, or contacting third parties or otherremotely located resources to provide update information to, or retrievedata from those remotely located resources. In another embodiment, someor all of the functions are carried out via hardware in lieu of aprocessor-based system. In one embodiment, the controller is a webbrowser, but in other embodiments the controller may be a databasesystem, a file system, an electronic mail system, a media manager, animage manager, or may include any other functions capable of accessingdata items. The storage device 516 may also contain additional softwareand data (not shown), which is not necessary to understand theinvention.

The output device 510 is that part of the computer 500 that displaysoutput to the user. The output device 510 may be a liquid crystaldisplay (LCD) well-known in the art of computer hardware. In otherembodiments, the output device 510 may be replaced with a gas orplasma-based flat-panel display or a traditional cathode-ray tube (CRT)display. In still other embodiments, any appropriate display device maybe used. Although only one output device 510 is shown, in otherembodiments any number of output devices of different types, or of thesame type, may be present. In an embodiment, the output device 510displays a user interface. The input device 512 may be a keyboard, mouseor other pointing device, trackball, touchpad, touch screen, keypad,microphone, voice recognition device, or any other appropriate mechanismfor the user to input data to the computer 500 and manipulate the userinterface previously discussed. Although only one input device 512 isshown, in another embodiment any number and type of input devices may bepresent.

The network interface device 520 provides connectivity from the computer500 to the network 526 through any suitable communications protocol. Thenetwork interface device 520 sends and receives data items from thenetwork 526 via a wireless or wired transceiver 514. The transceiver 514may be a cellular frequency, radio frequency (RF), infrared (IR) or anyof a number of known wireless or wired transmission systems capable ofcommunicating with a network 526 or other smart devices 102 having someor all of the features of the example computer of FIG. 2. The bus 508may represent one or more busses, e.g., USB, PCI, ISA (Industry StandardArchitecture), X-Bus, EISA (Extended Industry Standard Architecture), orany other appropriate bus and/or bridge (also called a bus controller).

The computer 500 may be implemented using any suitable hardware and/orsoftware, such as a personal computer or other electronic computingdevice. The computer 500 may be a portable computer, laptop, tablet ornotebook computers, smart phones, PDAs, pocket computers, appliances,telephones, and mainframe computers are examples of other possibleconfigurations of the computer 500. The network 526 may be any suitablenetwork and may support any appropriate protocol suitable forcommunication to the computer 500. In an embodiment, the network 526 maysupport wireless communications. In another embodiment, the network 526may support hard-wired communications, such as a telephone line orcable. In another embodiment, the network 526 may support the EthernetIEEE (Institute of Electrical and Electronics Engineers) 802.3xspecification. In another embodiment, the network 526 may be theInternet and may support IP (Internet Protocol). In another embodiment,the network 526 may be a LAN or a WAN. In another embodiment, thenetwork 526 may be a hotspot service provider network. In anotherembodiment, the network 526 may be an intranet. In another embodiment,the network 526 may be a GPRS (General Packet Radio Service) network. Inanother embodiment, the network 526 may be any appropriate cellular datanetwork or cell-based radio network technology. In another embodiment,the network 526 may be an IEEE 802.11 wireless network. In still anotherembodiment, the network 526 may be any suitable network or combinationof networks. Although one network 526 is shown, in other embodiments anynumber of networks (of the same or different types) may be present.

It should be understood that the various techniques described herein maybe implemented in connection with hardware or software or, whereappropriate, with a combination of both. Thus, the methods and apparatusof the presently disclosed subject matter, or certain aspects orportions thereof, may take the form of program code (i.e., instructions)embodied in tangible media, such as floppy diskettes, CD-ROMs, harddrives, or any other machine-readable storage medium wherein, when theprogram code is loaded into and executed by a machine, such as acomputer, the machine becomes an apparatus for practicing the presentlydisclosed subject matter. In the case of program code execution onprogrammable computers, the computing device generally includes aprocessor, a storage medium readable by the processor (includingvolatile and non-volatile memory and/or storage elements), at least oneinput device, and at least one output device. One or more programs mayimplement or use the processes described in connection with thepresently disclosed subject matter, e.g., through the use of an API,reusable controls, or the like. Such programs may be implemented in ahigh level procedural or object-oriented programming language tocommunicate with a computer system. However, the program(s) can beimplemented in assembly or machine language, if desired. In any case,the language may be a compiled or interpreted language and it may becombined with hardware implementations. Although exemplary embodimentsmay refer to using aspects of the presently disclosed subject matter inthe context of one or more stand-alone computer systems, the subjectmatter is not so limited, but rather may be implemented in connectionwith any computing environment, such as a network or distributedcomputing environment. Still further, aspects of the presently disclosedsubject matter may be implemented in or across a plurality of processingchips or devices, and storage may similarly be spread across a pluralityof devices. Such devices might include personal computers, networkservers, and handheld devices, for example.

Although the present invention has been described with reference topreferred embodiments, those skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention. As such, it is intended that the foregoingdetailed description be regarded as illustrative rather than limitingand that it is the appended claims, including all equivalents thereof,which are intended to define the scope of the invention.

What is claimed is:
 1. A nebulizer system comprising: a nebulizercomprising a housing having an ambient air inlet, a chamber for holdingan aerosol, a medication reservoir, a pressurized gas inlet in flowcommunication with the chamber, and an air outlet communicating with thechamber for permitting the aerosol to be withdrawn from the chamber; anactivation detector coupled to the nebulizer and operable to detect anactivation of the nebulizer; a flow detector coupled to the nebulizerand operable to detect an inhalation flow rate through the chamber; anair supply detector coupled to the nebulizer and operable to identify apressure and/or flow rate of a pressurized gas supply coupled to thepressurized gas inlet of the nebulizer; a feedback device configured toprovide feedback to a user about the inhalation flow rate in real time;and a controller operably connected with the activation detector, flowdetector, air supply detector and feedback device, wherein thecontroller receives input from the activation detector, air supplydetector and flow detector and signals the feedback device to providefeedback about an upper inhalation flow rate limit and/or a lowerinhalation flow rate limit in real time such that the inhalation flowrate may be adjusted and maintained between the upper inhalation flowrate limit and the lower inhalation flow rate limit in real time, andwherein the controller receives input from the activation detector, airsupply detector and flow detector and wherein the controller isconfigured to calculate a respirable dose of medication based on thereceived input from the activation detector, air supply detector andflow detector.
 2. The nebulizer system of claim 1 further comprising amedication identifier coupled to the nebulizer and operable to identifya type of medication introduced into the medication reservoir.
 3. Thenebulizer system of claim 1 further comprising a concentration detectorcoupled to the nebulizer and operable to identify a concentration of aliquid medication disposed in the medication reservoir.
 4. The nebulizersystem of claim 1 further comprising a particle size detector coupled tothe nebulizer and operable to measure a particle size distribution of anaerosolized medication in the chamber.
 5. The nebulizer system of claim4 wherein the particle size detector comprises a light source and alight detector spaced apart from the light source.
 6. The nebulizersystem of claim 5 further comprising a Fourier lens disposed between thelight source and the detector.
 7. The nebulizer system of claim 4wherein the nebulizer comprises a baffle spaced apart from an orifice ofthe gas inlet, and wherein the particle size detector comprises a forceor pressure sensor operably coupled to the baffle.
 8. The nebulizersystem of claim 1 further comprising an end of treatment detectorcoupled to the nebulizer and connected to the controller, wherein thecontroller is operable to notify the user via the feedback device whenan end of treatment has been reached.
 9. The nebulizer system of claim 8further comprising a residual volume detector coupled to the nebulizerand connected to the controller, wherein the controller is operable tonotify the user via the feedback device of a residual volume ofmedication when end of treatment has been reached.
 10. The nebulizersystem of claim 9 wherein the residual volume detector comprises acapacitive sensor operably coupled to the reservoir.
 11. The nebulizersystem of claim 9 wherein the residual volume detector comprises amoveable floating element disposed in the reservoir and a stationarysensing unit operable to sense the position of the floating element. 12.The nebulizer system of claim 9 wherein the residual volume detectorcomprises a pressure sensor coupled to the reservoir.
 13. The nebulizersystem of claim 9 wherein the residual volume detector comprises a lightsource and a light detector spaced apart from the light source, whereinone of the light source and light detector is disposed in the reservoir.14. The nebulizer system of claim 9 wherein the residual volume detectorcomprises a plurality of spaced apart conductive strips disposed alongan interior surface of the reservoir.
 15. The nebulizer system of claim9 wherein the residual volume detector comprises a transducer and areceiver spaced above a bottom of the reservoir.
 16. The nebulizersystem of claim 9 wherein the residual volume detector comprises acamera directed toward the reservoir.
 17. The nebulizer system of claim8 wherein the end of treatment detector comprises a microphone operableto detect a sputter caused by gaps in fluid flow.
 18. The nebulizersystem of claim 8 wherein the nebulizer comprises a baffle spaced apartfrom an orifice of the gas inlet, and wherein the end of treatmentdetector comprises a force or pressure sensor operably coupled to thebaffle.
 19. The nebulizer system of claim 1 wherein the feedback deviceis operable to communicate the respirable dose administered to the user.20. The nebulizer system of claim 1 further comprising storage operableto log treatment occurrences.
 21. The nebulizer system of claim 1wherein the feedback comprises at least one of a visual, auditory and/orvibratory feedback.
 22. The nebulizer system of claim 1 furthercomprising an actuator coupled to a biasing diaphragm, wherein theactuator and biasing diaphragm are coaxially positioned in thenebulizer, and wherein the actuator is configured to move between anon-nebulizing position and a nebulizing position, and wherein thebiasing diaphragm assists in the movement of the actuator between thenon-nebulizing position when no inhalation is occurring and thenebulizing position when inhalation is occurring.
 23. A nebulizer systemcomprising: a nebulizer comprising a housing having an ambient airinlet, a chamber for holding an aerosol, a medication reservoir and anair outlet communicating with the chamber for permitting the aerosol tobe withdrawn from the chamber; means for detecting an activation of thenebulizer; and means for identifying a pressure of a pressurized gassupply coupled to the nebulizer; means for detecting an inhalation flowrate through the chamber; means for providing feedback to a user aboutthe inhalation flow rate in real time; and a controller operablyconnected with the means for detecting the activation, means foridentifying the pressure and means for detecting the inhalation flowrate, wherein the controller receives input from the means for detectingthe activation, the means for identifying the pressure and the means fordetecting the inhalation flow rate, and signals the means for providingfeedback to provide feedback about an upper inhalation flow rate limitand/or a lower inhalation flow rate limit in real time such that theinhalation flow rate may be adjusted and maintained between the upperinhalation flow rate limit and the lower inhalation flow rate limit inreal time, and wherein the controller receives input from the means fordetecting the activation, the means for identifying the pressure and themeans for detecting the inhalation flow rate and is configured tocalculate a respirable dose of medication based on the received inputfrom the means for detecting the activation, the means for identifyingthe pressure and the means for detecting the inhalation flow rate. 24.The nebulizer system of claim 23 further comprising means foridentifying a type of medication introduced into the medicationreservoir.
 25. The nebulizer system of claim 23 further comprising meansfor identifying the concentration of a liquid medication disposed in themedication reservoir.
 26. The nebulizer system of claim 23 furthercomprising means for measuring a particle size distribution of anaerosolized medication in the chamber.
 27. The nebulizer system of claim26 wherein the means for measuring comprises a light source and a lightdetector spaced apart from the light source.
 28. The nebulizer system ofclaim 27 further comprising a Fourier lens disposed between the lightsource and the detector.
 29. The nebulizer system of claim 26 whereinthe nebulizer comprises a baffle spaced apart from an orifice of the gasinlet, and wherein the means for measuring comprises a force or pressuresensor operably coupled to the baffle.
 30. The nebulizer system of claim23 further comprising means for notifying the user when an end oftreatment has been reached.
 31. The nebulizer system of claim 30 whereinthe means for notifying comprises a microphone operable to detect asputter caused by gaps in fluid flow.
 32. The nebulizer system of claim30 wherein the nebulizer comprises a baffle spaced apart from an orificeof a gas inlet, and wherein the means for notifying comprises a force orpressure sensor operably coupled to the baffle.
 33. The nebulizer systemof claim 23 further comprising means for notifying the user of aresidual volume of medication when end of treatment has been reached.34. The nebulizer system of claim 33 wherein the means for notifyingcomprises a capacitive sensor operably coupled to the reservoir.
 35. Thenebulizer system of claim 33 wherein the means for notifying comprises amoveable floating element disposed in the reservoir and a stationarysensing unit operable to sense the position of the floating element. 36.The nebulizer system of claim 33 wherein the means for notifyingcomprises a pressure sensor coupled to the reservoir.
 37. The nebulizersystem of claim 33 wherein the means for notifying comprises a lightsource and a light detector spaced apart from the light source, whereinone of the light source and light detector is disposed in the reservoir.38. The nebulizer system of claim 33 wherein the means for notifyingcomprises a plurality of spaced apart conductive strips disposed alongan interior surface of the reservoir.
 39. The nebulizer system of claim33 wherein the means for notifying comprises a transducer and a receiverspaced above a bottom of the reservoir.
 40. The nebulizer system ofclaim 33 wherein the means for notifying comprises a camera directedtoward the reservoir.
 41. The nebulizer system of claim 23 wherein thenebulizer further comprises a pressurized gas inlet in flowcommunication with the chamber.
 42. The nebulizer system of claim 23further comprising an actuator coupled to a biasing diaphragm, whereinthe actuator and biasing diaphragm are coaxially positioned in thenebulizer, and wherein the actuator is configured to move between anon-nebulizing position and a nebulizing position, and wherein thebiasing diaphragm assists in the movement of the actuator between thenon-nebulizing position when no inhalation is occurring and thenebulizing position when inhalation is occurring.